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Math 1190 – Calculus I Ken Keating Kennesaw State University Chapter 1 Ken Keating (Kennesaw State University) Math 1190 – Calculus I Chapter 1 1 / 33

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Page 1: RelativeResourceManager

Math 1190 – Calculus I

Ken Keating

Kennesaw State University

Chapter 1

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Chapter 1 1 / 33

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Table of Contents

1 Preface

2 Section 1.1

3 Section 1.2

4 Section 1.3

5 Section 1.4

6 Section 1.6

7 Section 1.7

8 Section 1.8

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Chapter 1 2 / 33

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What is Calculus?

According to Wikipedia:

Calculus is a branch of mathematics focused on limits, func-tions, derivatives, integrals, and infinite series. . . . It hastwo major branches, differential calculus and integral calcu-lus, which are related by the fundamental theorem of calculus.Calculus is the study of change, in the same way that geome-try is the study of shape and algebra is the study of operations andtheir application to solving equations. . . . Calculus has widespreadapplications in science, economics, and engineering and can solvemany problems for which algebra alone is insufficient.

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Chapter 1 3 / 33

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What is Calculus?

According to Wikipedia:

Calculus is a branch of mathematics focused on limits, func-tions, derivatives, integrals, and infinite series. . . . It hastwo major branches, differential calculus and integral calcu-lus, which are related by the fundamental theorem of calculus.Calculus is the study of change, in the same way that geome-try is the study of shape and algebra is the study of operations andtheir application to solving equations. . . . Calculus has widespreadapplications in science, economics, and engineering and can solvemany problems for which algebra alone is insufficient.

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Chapter 1 3 / 33

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Section 1.1 – Functions and Their Graphs

Definition

A function f from a set D to a set Y is a rule that assigns a unique(single) element f (x) ∈ Y to each element x ∈ D.

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.1 4 / 33

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Section 1.1 – Functions and Their Graphs

Definition

A function f from a set D to a set Y is a rule that assigns a unique(single) element f (x) ∈ Y to each element x ∈ D.

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.1 4 / 33

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Section 1.1 – Functions and Their Graphs

Definition

A function f from a set D to a set Y is a rule that assigns a unique(single) element f (x) ∈ Y to each element x ∈ D.

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.1 4 / 33

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Section 1.1 – Functions and Their Graphs

Functions pass the vertical line test

Relations that fail the vertical line test can be analyzed piecewiseI e.g. a circle

Types of functionsI piecewise-definedI increasing/decreasingI odd/evenI linearI powerI polynomialI rationalI algebraicI trigonometricI exponentialI logarithmicI transcendental

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.1 5 / 33

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Section 1.1 – Functions and Their Graphs

Functions pass the vertical line test

Relations that fail the vertical line test can be analyzed piecewise

I e.g. a circle

Types of functionsI piecewise-definedI increasing/decreasingI odd/evenI linearI powerI polynomialI rationalI algebraicI trigonometricI exponentialI logarithmicI transcendental

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.1 5 / 33

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Section 1.1 – Functions and Their Graphs

Functions pass the vertical line test

Relations that fail the vertical line test can be analyzed piecewiseI e.g. a circle

Types of functionsI piecewise-definedI increasing/decreasingI odd/evenI linearI powerI polynomialI rationalI algebraicI trigonometricI exponentialI logarithmicI transcendental

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.1 5 / 33

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Section 1.1 – Functions and Their Graphs

Functions pass the vertical line test

Relations that fail the vertical line test can be analyzed piecewiseI e.g. a circle

Types of functions

I piecewise-definedI increasing/decreasingI odd/evenI linearI powerI polynomialI rationalI algebraicI trigonometricI exponentialI logarithmicI transcendental

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.1 5 / 33

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Section 1.1 – Functions and Their Graphs

Functions pass the vertical line test

Relations that fail the vertical line test can be analyzed piecewiseI e.g. a circle

Types of functionsI piecewise-definedI increasing/decreasingI odd/evenI linearI powerI polynomialI rationalI algebraicI trigonometricI exponentialI logarithmicI transcendental

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.1 5 / 33

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Section 1.2 – Combining Functions; Shifting and ScalingGraphs

(f + g)(x), (f − g)(x), (fg)(x),

(f

g

)(x), including domain

(f ◦ g)(x) = f (g(x)), including domain

shifts: y = f (x) + k (vertical) , y = f (x + h) (horizontal)

scaling: y = cf (x) (vertical) , y = f (cx) (horizontal)

reflecting: y = −f (x) (x-axis) , y = f (−x) (y-axis)

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.2 6 / 33

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Section 1.2 – Combining Functions; Shifting and ScalingGraphs

(f + g)(x), (f − g)(x), (fg)(x),

(f

g

)(x), including domain

(f ◦ g)(x) = f (g(x)), including domain

shifts: y = f (x) + k (vertical) , y = f (x + h) (horizontal)

scaling: y = cf (x) (vertical) , y = f (cx) (horizontal)

reflecting: y = −f (x) (x-axis) , y = f (−x) (y-axis)

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.2 6 / 33

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Section 1.2 – Combining Functions; Shifting and ScalingGraphs

(f + g)(x), (f − g)(x), (fg)(x),

(f

g

)(x), including domain

(f ◦ g)(x) = f (g(x)), including domain

shifts: y = f (x) + k (vertical) , y = f (x + h) (horizontal)

scaling: y = cf (x) (vertical) , y = f (cx) (horizontal)

reflecting: y = −f (x) (x-axis) , y = f (−x) (y-axis)

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.2 6 / 33

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Section 1.2 – Combining Functions; Shifting and ScalingGraphs

(f + g)(x), (f − g)(x), (fg)(x),

(f

g

)(x), including domain

(f ◦ g)(x) = f (g(x)), including domain

shifts: y = f (x) + k (vertical) , y = f (x + h) (horizontal)

scaling: y = cf (x) (vertical) , y = f (cx) (horizontal)

reflecting: y = −f (x) (x-axis) , y = f (−x) (y-axis)

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.2 6 / 33

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Section 1.2 – Combining Functions; Shifting and ScalingGraphs

(f + g)(x), (f − g)(x), (fg)(x),

(f

g

)(x), including domain

(f ◦ g)(x) = f (g(x)), including domain

shifts: y = f (x) + k (vertical) , y = f (x + h) (horizontal)

scaling: y = cf (x) (vertical) , y = f (cx) (horizontal)

reflecting: y = −f (x) (x-axis) , y = f (−x) (y-axis)

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.2 6 / 33

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Section 1.2 – Combining Functions; Shifting and ScalingGraphs

(f + g)(x), (f − g)(x), (fg)(x),

(f

g

)(x), including domain

(f ◦ g)(x) = f (g(x)), including domain

shifts: y = f (x) + k (vertical) , y = f (x + h) (horizontal)

scaling: y = cf (x) (vertical) , y = f (cx) (horizontal)

reflecting: y = −f (x) (x-axis) , y = f (−x) (y-axis)

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.2 6 / 33

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Section 1.3 – Rates of Change and Tangents to Curves

Recall slope =rise

run=

change in y

change in x=

y2 − y1x2 − x1

=∆y

∆x

ex: linear function – note ∆y and ∆x

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.3 7 / 33

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Section 1.3 – Rates of Change and Tangents to Curves

Recall slope =rise

run=

change in y

change in x=

y2 − y1x2 − x1

=∆y

∆x

ex: linear function – note ∆y and ∆x

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.3 7 / 33

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Section 1.3 – Rates of Change and Tangents to Curves

Recall slope =rise

run=

change in y

change in x=

y2 − y1x2 − x1

=∆y

∆x

ex: linear function – note ∆y and ∆x

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.3 7 / 33

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Section 1.3 – Rates of Change and Tangents to Curves

ex: quadratic function

Note: slope of secant line betweenP and Q = average rate of changebetween P and Q

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.3 8 / 33

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Section 1.3 – Rates of Change and Tangents to Curves

ex: quadratic function

Note: slope of secant line betweenP and Q = average rate of changebetween P and Q

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.3 8 / 33

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Section 1.3 – Rates of Change and Tangents to Curves

ex: quadratic function

Note: slope of secant line betweenP and Q = average rate of changebetween P and Q

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.3 8 / 33

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Section 1.3 – Rates of Change and Tangents to Curves

Definition

The average rate of change of y = f (x) with respect to x over the interval[x1, x2] is

∆y

∆x=

f (x2)− f (x1)

x2 − x1=

f (x1 + h)− f (x1)

h, h 6= 0

So we know we can find the slope of the line between any two points Pand Q on a curve. What about the slope of the curve at any givenpoint?

It’s reasonable (and correct, as we’ll see later this semester) to associatethe slope of the line tangent to a point on a curve with the slope of thecurve at that point.

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.3 9 / 33

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Section 1.3 – Rates of Change and Tangents to Curves

Definition

The average rate of change of y = f (x) with respect to x over the interval[x1, x2] is

∆y

∆x=

f (x2)− f (x1)

x2 − x1=

f (x1 + h)− f (x1)

h, h 6= 0

So we know we can find the slope of the line between any two points Pand Q on a curve. What about the slope of the curve at any givenpoint?

It’s reasonable (and correct, as we’ll see later this semester) to associatethe slope of the line tangent to a point on a curve with the slope of thecurve at that point.

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.3 9 / 33

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Section 1.3 – Rates of Change and Tangents to Curves

Definition

The average rate of change of y = f (x) with respect to x over the interval[x1, x2] is

∆y

∆x=

f (x2)− f (x1)

x2 − x1=

f (x1 + h)− f (x1)

h, h 6= 0

So we know we can find the slope of the line between any two points Pand Q on a curve. What about the slope of the curve at any givenpoint?

It’s reasonable (and correct, as we’ll see later this semester) to associatethe slope of the line tangent to a point on a curve with the slope of thecurve at that point.

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.3 9 / 33

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Section 1.3 – Rates of Change and Tangents to Curves

As Q moves closer to P,the slope of the secant line between P and Q approaches the slope ofthe tangent line at P

the length of ∆x = h gets closer to 0

the average rate of change between P and Q approaches theinstantaneous rate of change at P

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.3 10 / 33

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Section 1.3 – Rates of Change and Tangents to Curves

As Q moves closer to P,

the slope of the secant line between P and Q approaches the slope ofthe tangent line at P

the length of ∆x = h gets closer to 0

the average rate of change between P and Q approaches theinstantaneous rate of change at P

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.3 10 / 33

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Section 1.3 – Rates of Change and Tangents to Curves

As Q moves closer to P,the slope of the secant line between P and Q approaches the slope ofthe tangent line at P

the length of ∆x = h gets closer to 0

the average rate of change between P and Q approaches theinstantaneous rate of change at P

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.3 10 / 33

Page 31: RelativeResourceManager

Section 1.3 – Rates of Change and Tangents to Curves

As Q moves closer to P,the slope of the secant line between P and Q approaches the slope ofthe tangent line at P

the length of ∆x = h gets closer to 0

the average rate of change between P and Q approaches theinstantaneous rate of change at P

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.3 10 / 33

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Section 1.3 – Rates of Change and Tangents to Curves

As Q moves closer to P,the slope of the secant line between P and Q approaches the slope ofthe tangent line at P

the length of ∆x = h gets closer to 0

the average rate of change between P and Q approaches theinstantaneous rate of change at P

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.3 10 / 33

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Section 1.3 – Rates of Change and Tangents to Curves

ex: (p.23 #10) Find the slope of the curve at the given point P and findthe equation of the tangent line at P.

y = 5− x2, P(1, 4)

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.3 11 / 33

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Section 1.4 – Limit of a Function and Limit Laws

Before defining what a limit is, let’s look at an example and try todetermine what the function values are approaching as x → 1.

f (−1) = 0 f (−1) = 0 f (−1) = 0

f (0) = 1 f (0) = 1 f (0) = 1

f (1) = undefined f (1) = 1 f (1) = 2

as x → 1, y → 2 as x → 1, y → 2 as x → 1, y → 2

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 12 / 33

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Section 1.4 – Limit of a Function and Limit Laws

Before defining what a limit is, let’s look at an example and try todetermine what the function values are approaching as x → 1.

f (−1) = 0 f (−1) = 0 f (−1) = 0

f (0) = 1 f (0) = 1 f (0) = 1

f (1) = undefined f (1) = 1 f (1) = 2

as x → 1, y → 2 as x → 1, y → 2 as x → 1, y → 2

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 12 / 33

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Section 1.4 – Limit of a Function and Limit Laws

Before defining what a limit is, let’s look at an example and try todetermine what the function values are approaching as x → 1.

f (−1) = 0 f (−1) = 0 f (−1) = 0

f (0) = 1 f (0) = 1 f (0) = 1

f (1) = undefined f (1) = 1 f (1) = 2

as x → 1, y → 2 as x → 1, y → 2 as x → 1, y → 2

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 12 / 33

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Section 1.4 – Limit of a Function and Limit Laws

Before defining what a limit is, let’s look at an example and try todetermine what the function values are approaching as x → 1.

f (−1) = 0 f (−1) = 0 f (−1) = 0

f (0) = 1 f (0) = 1 f (0) = 1

f (1) = undefined f (1) = 1 f (1) = 2

as x → 1, y → 2 as x → 1, y → 2 as x → 1, y → 2

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 12 / 33

Page 38: RelativeResourceManager

Section 1.4 – Limit of a Function and Limit Laws

Before defining what a limit is, let’s look at an example and try todetermine what the function values are approaching as x → 1.

f (−1) = 0 f (−1) = 0 f (−1) = 0

f (0) = 1 f (0) = 1 f (0) = 1

f (1) = undefined f (1) = 1 f (1) = 2

as x → 1, y → 2 as x → 1, y → 2 as x → 1, y → 2

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 12 / 33

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Section 1.4 – Limit of a Function and Limit Laws

Before defining what a limit is, let’s look at an example and try todetermine what the function values are approaching as x → 1.

f (−1) = 0 f (−1) = 0 f (−1) = 0

f (0) = 1 f (0) = 1 f (0) = 1

f (1) = undefined f (1) = 1 f (1) = 2

as x → 1, y → 2 as x → 1, y → 2 as x → 1, y → 2

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 12 / 33

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Section 1.4 – Limit of a Function and Limit Laws

Before defining what a limit is, let’s look at an example and try todetermine what the function values are approaching as x → 1.

f (−1) = 0 f (−1) = 0 f (−1) = 0

f (0) = 1 f (0) = 1 f (0) = 1

f (1) = undefined f (1) = 1 f (1) = 2

as x → 1, y → 2 as x → 1, y → 2 as x → 1, y → 2

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 12 / 33

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Section 1.4 – Limit of a Function and Limit Laws

Definition

Let f (x) be defined on an open interval about x0, except possibly at x0itself. If f (x) is arbitrarily close to L for all x sufficiently close to x0, wesay that f approaches the limit L as x approaches x0, and we write

limx→x0

f (x) = L.

Definition (formal – as given in Sec. 1.5)

Let f (x) be defined on an open interval about x0, except possibly at x0itself. We say that the limit of f(x) as x approaches x0 is the numberL, and write

limx→x0

f (x) = L,

if, for every number ε > 0, there exists a corresponding number δ > 0 suchthat for all x ,

0 < |x − x0| < δ ⇒ |f (x)− L| < ε.

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 13 / 33

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Section 1.4 – Limit of a Function and Limit Laws

Definition

Let f (x) be defined on an open interval about x0, except possibly at x0itself. If f (x) is arbitrarily close to L for all x sufficiently close to x0, wesay that f approaches the limit L as x approaches x0, and we write

limx→x0

f (x) = L.

Definition (formal – as given in Sec. 1.5)

Let f (x) be defined on an open interval about x0, except possibly at x0itself. We say that the limit of f(x) as x approaches x0 is the numberL, and write

limx→x0

f (x) = L,

if, for every number ε > 0, there exists a corresponding number δ > 0 suchthat for all x ,

0 < |x − x0| < δ ⇒ |f (x)− L| < ε.Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 13 / 33

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Section 1.4 – Limit of a Function and Limit Laws

Note, functions may have point(s) where the limit does NOT exist:

(a) jumps

(b) grows too large to have a limit

(c) oscillates too much to have a limit

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 14 / 33

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Section 1.4 – Limit of a Function and Limit Laws

Note, functions may have point(s) where the limit does NOT exist:

(a) jumps

(b) grows too large to have a limit

(c) oscillates too much to have a limit

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 14 / 33

Page 45: RelativeResourceManager

Section 1.4 – Limit of a Function and Limit Laws

Note, functions may have point(s) where the limit does NOT exist:

(a) jumps

(b) grows too large to have a limit

(c) oscillates too much to have a limit

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 14 / 33

Page 46: RelativeResourceManager

Section 1.4 – Limit of a Function and Limit Laws

Note, functions may have point(s) where the limit does NOT exist:

(a) jumps

(b) grows too large to have a limit

(c) oscillates too much to have a limit

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 14 / 33

Page 47: RelativeResourceManager

Section 1.4 – Limit of a Function and Limit Laws

Note, functions may have point(s) where the limit does NOT exist:

(a) jumps

(b) grows too large to have a limit

(c) oscillates too much to have a limit

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 14 / 33

Page 48: RelativeResourceManager

Section 1.4 – Limit of a Function and Limit Laws

One common task we’ll have is to find the value of the limit (assuming itexists). To do this we’ll need to make use of ”limit laws”. First, however,we present a few special cases.

f is a constant function, i.e., f (x) = klimx→x0

f (x) = limx→x0

k = k

f is the identity function, i.e., f (x) = xlimx→x0

f (x) = limx→x0

x = x0

Now, our ”limit laws”:

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 15 / 33

Page 49: RelativeResourceManager

Section 1.4 – Limit of a Function and Limit Laws

One common task we’ll have is to find the value of the limit (assuming itexists). To do this we’ll need to make use of ”limit laws”. First, however,we present a few special cases.

f is a constant function, i.e., f (x) = k

limx→x0

f (x) = limx→x0

k = k

f is the identity function, i.e., f (x) = xlimx→x0

f (x) = limx→x0

x = x0

Now, our ”limit laws”:

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 15 / 33

Page 50: RelativeResourceManager

Section 1.4 – Limit of a Function and Limit Laws

One common task we’ll have is to find the value of the limit (assuming itexists). To do this we’ll need to make use of ”limit laws”. First, however,we present a few special cases.

f is a constant function, i.e., f (x) = klimx→x0

f (x) = limx→x0

k = k

f is the identity function, i.e., f (x) = xlimx→x0

f (x) = limx→x0

x = x0

Now, our ”limit laws”:

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 15 / 33

Page 51: RelativeResourceManager

Section 1.4 – Limit of a Function and Limit Laws

One common task we’ll have is to find the value of the limit (assuming itexists). To do this we’ll need to make use of ”limit laws”. First, however,we present a few special cases.

f is a constant function, i.e., f (x) = klimx→x0

f (x) = limx→x0

k = k

f is the identity function, i.e., f (x) = x

limx→x0

f (x) = limx→x0

x = x0

Now, our ”limit laws”:

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 15 / 33

Page 52: RelativeResourceManager

Section 1.4 – Limit of a Function and Limit Laws

One common task we’ll have is to find the value of the limit (assuming itexists). To do this we’ll need to make use of ”limit laws”. First, however,we present a few special cases.

f is a constant function, i.e., f (x) = klimx→x0

f (x) = limx→x0

k = k

f is the identity function, i.e., f (x) = xlimx→x0

f (x) = limx→x0

x = x0

Now, our ”limit laws”:

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 15 / 33

Page 53: RelativeResourceManager

Section 1.4 – Limit of a Function and Limit Laws

One common task we’ll have is to find the value of the limit (assuming itexists). To do this we’ll need to make use of ”limit laws”. First, however,we present a few special cases.

f is a constant function, i.e., f (x) = klimx→x0

f (x) = limx→x0

k = k

f is the identity function, i.e., f (x) = xlimx→x0

f (x) = limx→x0

x = x0

Now, our ”limit laws”:

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 15 / 33

Page 54: RelativeResourceManager

Section 1.4 – Limit of a Function and Limit Laws

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 16 / 33

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Section 1.4 – Limit of a Function and Limit Laws

In addition to our ”limit laws”, there are some theorems that will help usquickly compute limits.

Theorem (Limits of Polynomials)

If P(x) = anxn + an−1xn−1 + · · ·+ a0, then

limx→c

P(x) = P(c) = ancn + an−1cn−1 + · · ·+ a0.

In other words, to compute the limit as x approaches c of a polynomial,simply plug c in for x in the polynomial!

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 17 / 33

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Section 1.4 – Limit of a Function and Limit Laws

In addition to our ”limit laws”, there are some theorems that will help usquickly compute limits.

Theorem (Limits of Polynomials)

If P(x) = anxn + an−1xn−1 + · · ·+ a0, then

limx→c

P(x) = P(c) = ancn + an−1cn−1 + · · ·+ a0.

In other words, to compute the limit as x approaches c of a polynomial,simply plug c in for x in the polynomial!

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 17 / 33

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Section 1.4 – Limit of a Function and Limit Laws

In addition to our ”limit laws”, there are some theorems that will help usquickly compute limits.

Theorem (Limits of Polynomials)

If P(x) = anxn + an−1xn−1 + · · ·+ a0, then

limx→c

P(x) = P(c) = ancn + an−1cn−1 + · · ·+ a0.

In other words, to compute the limit as x approaches c of a polynomial,simply plug c in for x in the polynomial!

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 17 / 33

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Section 1.4 – Limit of a Function and Limit Laws

Theorem (Limits of Rational Functions)

If P(x) and Q(x) are polynomials and Q(c) 6= 0, then

limx→c

P(x)

Q(x)=

P(c)

Q(c).

Like we did for polynomials, if we need to compute the limit as xapproaches c of a rational function, we just plug c in for x in both thenumerator and denominator.

Note in the statement of the theorem the phrase ”and Q(c) 6= 0”. If, infact, we DO have Q(c) = 0, there are some techniques we can employ totry to compute the limit. These will be presented by example after wepresent the next two theorems.

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 18 / 33

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Section 1.4 – Limit of a Function and Limit Laws

Theorem (Limits of Rational Functions)

If P(x) and Q(x) are polynomials and Q(c) 6= 0, then

limx→c

P(x)

Q(x)=

P(c)

Q(c).

Like we did for polynomials, if we need to compute the limit as xapproaches c of a rational function, we just plug c in for x in both thenumerator and denominator.

Note in the statement of the theorem the phrase ”and Q(c) 6= 0”. If, infact, we DO have Q(c) = 0, there are some techniques we can employ totry to compute the limit. These will be presented by example after wepresent the next two theorems.

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 18 / 33

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Section 1.4 – Limit of a Function and Limit Laws

Theorem (Limits of Rational Functions)

If P(x) and Q(x) are polynomials and Q(c) 6= 0, then

limx→c

P(x)

Q(x)=

P(c)

Q(c).

Like we did for polynomials, if we need to compute the limit as xapproaches c of a rational function, we just plug c in for x in both thenumerator and denominator.

Note in the statement of the theorem the phrase ”and Q(c) 6= 0”. If, infact, we DO have Q(c) = 0, there are some techniques we can employ totry to compute the limit. These will be presented by example after wepresent the next two theorems.

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 18 / 33

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Section 1.4 – Limit of a Function and Limit Laws

Theorem (The Sandwich, or Squeeze, Theorem)

Suppose that g(x) ≤ f (x) ≤ h(x) for all x in some open intervalcontaining c, except possibly at x = c itself. Suppose also that

limx→c

g(x) = limx→c

h(x) = L.

Then limx→c f (x) = L.

Suppose we don’t know to compute the limit as x approaches c of thefunction f . If we know that f is always between two other functions, gand h, whose limits as x approaches c both equal L, then we areguaranteed that the limit as x approaches c of the function f is also L.

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 19 / 33

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Section 1.4 – Limit of a Function and Limit Laws

Theorem (The Sandwich, or Squeeze, Theorem)

Suppose that g(x) ≤ f (x) ≤ h(x) for all x in some open intervalcontaining c, except possibly at x = c itself. Suppose also that

limx→c

g(x) = limx→c

h(x) = L.

Then limx→c f (x) = L.

Suppose we don’t know to compute the limit as x approaches c of thefunction f . If we know that f is always between two other functions, gand h, whose limits as x approaches c both equal L, then we areguaranteed that the limit as x approaches c of the function f is also L.

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 19 / 33

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Section 1.4 – Limit of a Function and Limit Laws

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 20 / 33

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Section 1.4 – Limit of a Function and Limit Laws

Theorem

If f (x) ≤ g(x) for all x in some open interval containing c, except possiblyat x = c itself, and the limits of f and g both exist as x approaches c, then

limx→c

f (x) ≤ limx→c

g(x).

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 21 / 33

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Section 1.4 – Limit of a Function and Limit Laws

ex: p.31 #2

ex: p.32 #10

ex: p.32 #14

ex: p.32 #20

ex: p.32 #32

ex: p.32 #42

ex: p.33 #56

ex: p.33 #66a

ex: p.33 #73

ex: p.34 #75

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 22 / 33

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Section 1.4 – Limit of a Function and Limit Laws

ex: p.31 #2

ex: p.32 #10

ex: p.32 #14

ex: p.32 #20

ex: p.32 #32

ex: p.32 #42

ex: p.33 #56

ex: p.33 #66a

ex: p.33 #73

ex: p.34 #75

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 22 / 33

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Section 1.4 – Limit of a Function and Limit Laws

ex: p.31 #2

ex: p.32 #10

ex: p.32 #14

ex: p.32 #20

ex: p.32 #32

ex: p.32 #42

ex: p.33 #56

ex: p.33 #66a

ex: p.33 #73

ex: p.34 #75

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 22 / 33

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Section 1.4 – Limit of a Function and Limit Laws

ex: p.31 #2

ex: p.32 #10

ex: p.32 #14

ex: p.32 #20

ex: p.32 #32

ex: p.32 #42

ex: p.33 #56

ex: p.33 #66a

ex: p.33 #73

ex: p.34 #75

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 22 / 33

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Section 1.4 – Limit of a Function and Limit Laws

ex: p.31 #2

ex: p.32 #10

ex: p.32 #14

ex: p.32 #20

ex: p.32 #32

ex: p.32 #42

ex: p.33 #56

ex: p.33 #66a

ex: p.33 #73

ex: p.34 #75

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 22 / 33

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Section 1.4 – Limit of a Function and Limit Laws

ex: p.31 #2

ex: p.32 #10

ex: p.32 #14

ex: p.32 #20

ex: p.32 #32

ex: p.32 #42

ex: p.33 #56

ex: p.33 #66a

ex: p.33 #73

ex: p.34 #75

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 22 / 33

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Section 1.4 – Limit of a Function and Limit Laws

ex: p.31 #2

ex: p.32 #10

ex: p.32 #14

ex: p.32 #20

ex: p.32 #32

ex: p.32 #42

ex: p.33 #56

ex: p.33 #66a

ex: p.33 #73

ex: p.34 #75

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 22 / 33

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Section 1.4 – Limit of a Function and Limit Laws

ex: p.31 #2

ex: p.32 #10

ex: p.32 #14

ex: p.32 #20

ex: p.32 #32

ex: p.32 #42

ex: p.33 #56

ex: p.33 #66a

ex: p.33 #73

ex: p.34 #75

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 22 / 33

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Section 1.4 – Limit of a Function and Limit Laws

ex: p.31 #2

ex: p.32 #10

ex: p.32 #14

ex: p.32 #20

ex: p.32 #32

ex: p.32 #42

ex: p.33 #56

ex: p.33 #66a

ex: p.33 #73

ex: p.34 #75

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 22 / 33

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Section 1.4 – Limit of a Function and Limit Laws

ex: p.31 #2

ex: p.32 #10

ex: p.32 #14

ex: p.32 #20

ex: p.32 #32

ex: p.32 #42

ex: p.33 #56

ex: p.33 #66a

ex: p.33 #73

ex: p.34 #75

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 22 / 33

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Section 1.4 – Limit of a Function and Limit Laws

”Toolbox” Summary – When computing limx→c

f (x):

first try plugging c in for x

simplify f (x) by canceling common factors, then take the limit

multiply numerator and denominator of f (x) by the ”conjugate”,simplify f (x), then take the limit

when all else fails, make a table of values letting x get closer andcloser to c (from both sides) and see if you can determine if f (x) isapproaching a real number L

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.4 23 / 33

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Section 1.6 – One-Sided Limits

limx→c

f (x) = L means f (x)→ L as x → c from both sides of c

thus, when we say limx→c

f (x) = L, we mean a two-sided limit

a function that fails to have a two-sided limit at c may still haveone-sided limits at c

right-hand limit: limx→c+

f (x) = L if x ∈ (c , b) and f (x)→ L as x → c

left-hand limit: limx→c−

f (x) = L if x ∈ (a, c) and f (x)→ L as x → c

all laws/properties/rules/theorems from Section 1.4 hold for one-sidedlimits

let’s revisit the graphs depicting functions that failed to have a limitas x → 0

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 24 / 33

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Section 1.6 – One-Sided Limits

limx→c

f (x) = L means f (x)→ L as x → c from both sides of c

thus, when we say limx→c

f (x) = L, we mean a two-sided limit

a function that fails to have a two-sided limit at c may still haveone-sided limits at c

right-hand limit: limx→c+

f (x) = L if x ∈ (c , b) and f (x)→ L as x → c

left-hand limit: limx→c−

f (x) = L if x ∈ (a, c) and f (x)→ L as x → c

all laws/properties/rules/theorems from Section 1.4 hold for one-sidedlimits

let’s revisit the graphs depicting functions that failed to have a limitas x → 0

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 24 / 33

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Section 1.6 – One-Sided Limits

limx→c

f (x) = L means f (x)→ L as x → c from both sides of c

thus, when we say limx→c

f (x) = L, we mean a two-sided limit

a function that fails to have a two-sided limit at c may still haveone-sided limits at c

right-hand limit: limx→c+

f (x) = L if x ∈ (c , b) and f (x)→ L as x → c

left-hand limit: limx→c−

f (x) = L if x ∈ (a, c) and f (x)→ L as x → c

all laws/properties/rules/theorems from Section 1.4 hold for one-sidedlimits

let’s revisit the graphs depicting functions that failed to have a limitas x → 0

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 24 / 33

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Section 1.6 – One-Sided Limits

limx→c

f (x) = L means f (x)→ L as x → c from both sides of c

thus, when we say limx→c

f (x) = L, we mean a two-sided limit

a function that fails to have a two-sided limit at c may still haveone-sided limits at c

right-hand limit: limx→c+

f (x) = L if x ∈ (c , b) and f (x)→ L as x → c

left-hand limit: limx→c−

f (x) = L if x ∈ (a, c) and f (x)→ L as x → c

all laws/properties/rules/theorems from Section 1.4 hold for one-sidedlimits

let’s revisit the graphs depicting functions that failed to have a limitas x → 0

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 24 / 33

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Section 1.6 – One-Sided Limits

limx→c

f (x) = L means f (x)→ L as x → c from both sides of c

thus, when we say limx→c

f (x) = L, we mean a two-sided limit

a function that fails to have a two-sided limit at c may still haveone-sided limits at c

right-hand limit: limx→c+

f (x) = L if x ∈ (c , b) and f (x)→ L as x → c

left-hand limit: limx→c−

f (x) = L if x ∈ (a, c) and f (x)→ L as x → c

all laws/properties/rules/theorems from Section 1.4 hold for one-sidedlimits

let’s revisit the graphs depicting functions that failed to have a limitas x → 0

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 24 / 33

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Section 1.6 – One-Sided Limits

limx→c

f (x) = L means f (x)→ L as x → c from both sides of c

thus, when we say limx→c

f (x) = L, we mean a two-sided limit

a function that fails to have a two-sided limit at c may still haveone-sided limits at c

right-hand limit: limx→c+

f (x) = L if x ∈ (c , b) and f (x)→ L as x → c

left-hand limit: limx→c−

f (x) = L if x ∈ (a, c) and f (x)→ L as x → c

all laws/properties/rules/theorems from Section 1.4 hold for one-sidedlimits

let’s revisit the graphs depicting functions that failed to have a limitas x → 0

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 24 / 33

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Section 1.6 – One-Sided Limits

limx→c

f (x) = L means f (x)→ L as x → c from both sides of c

thus, when we say limx→c

f (x) = L, we mean a two-sided limit

a function that fails to have a two-sided limit at c may still haveone-sided limits at c

right-hand limit: limx→c+

f (x) = L if x ∈ (c , b) and f (x)→ L as x → c

left-hand limit: limx→c−

f (x) = L if x ∈ (a, c) and f (x)→ L as x → c

all laws/properties/rules/theorems from Section 1.4 hold for one-sidedlimits

let’s revisit the graphs depicting functions that failed to have a limitas x → 0

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 24 / 33

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Section 1.6 – One-Sided Limits

limx→c

f (x) = L means f (x)→ L as x → c from both sides of c

thus, when we say limx→c

f (x) = L, we mean a two-sided limit

a function that fails to have a two-sided limit at c may still haveone-sided limits at c

right-hand limit: limx→c+

f (x) = L if x ∈ (c , b) and f (x)→ L as x → c

left-hand limit: limx→c−

f (x) = L if x ∈ (a, c) and f (x)→ L as x → c

all laws/properties/rules/theorems from Section 1.4 hold for one-sidedlimits

let’s revisit the graphs depicting functions that failed to have a limitas x → 0

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 24 / 33

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Section 1.6 – One-Sided Limits

limx→0

f (x) = DNE limx→0

f (x) = DNE limx→0

f (x) = DNE

limx→0−

f (x) = 0 limx→0−

f (x) = DNE limx→0−

f (x) = 0

limx→0+

f (x) = 1 limx→0+

f (x) = DNE limx→0+

f (x) = DNE

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 25 / 33

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Section 1.6 – One-Sided Limits

limx→0

f (x) = DNE

limx→0

f (x) = DNE limx→0

f (x) = DNE

limx→0−

f (x) = 0 limx→0−

f (x) = DNE limx→0−

f (x) = 0

limx→0+

f (x) = 1 limx→0+

f (x) = DNE limx→0+

f (x) = DNE

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 25 / 33

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Section 1.6 – One-Sided Limits

limx→0

f (x) = DNE

limx→0

f (x) = DNE limx→0

f (x) = DNE

limx→0−

f (x) =

0 limx→0−

f (x) = DNE limx→0−

f (x) = 0

limx→0+

f (x) = 1 limx→0+

f (x) = DNE limx→0+

f (x) = DNE

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 25 / 33

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Section 1.6 – One-Sided Limits

limx→0

f (x) = DNE

limx→0

f (x) = DNE limx→0

f (x) = DNE

limx→0−

f (x) = 0

limx→0−

f (x) = DNE limx→0−

f (x) = 0

limx→0+

f (x) = 1 limx→0+

f (x) = DNE limx→0+

f (x) = DNE

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 25 / 33

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Section 1.6 – One-Sided Limits

limx→0

f (x) = DNE

limx→0

f (x) = DNE limx→0

f (x) = DNE

limx→0−

f (x) = 0

limx→0−

f (x) = DNE limx→0−

f (x) = 0

limx→0+

f (x) =

1 limx→0+

f (x) = DNE limx→0+

f (x) = DNE

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 25 / 33

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Section 1.6 – One-Sided Limits

limx→0

f (x) = DNE

limx→0

f (x) = DNE limx→0

f (x) = DNE

limx→0−

f (x) = 0

limx→0−

f (x) = DNE limx→0−

f (x) = 0

limx→0+

f (x) = 1

limx→0+

f (x) = DNE limx→0+

f (x) = DNE

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 25 / 33

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Section 1.6 – One-Sided Limits

limx→0

f (x) = DNE limx→0

f (x) = DNE

limx→0

f (x) = DNE

limx→0−

f (x) = 0

limx→0−

f (x) = DNE limx→0−

f (x) = 0

limx→0+

f (x) = 1

limx→0+

f (x) = DNE limx→0+

f (x) = DNE

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 25 / 33

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Section 1.6 – One-Sided Limits

limx→0

f (x) = DNE limx→0

f (x) = DNE

limx→0

f (x) = DNE

limx→0−

f (x) = 0 limx→0−

f (x) =

DNE limx→0−

f (x) = 0

limx→0+

f (x) = 1

limx→0+

f (x) = DNE limx→0+

f (x) = DNE

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 25 / 33

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Section 1.6 – One-Sided Limits

limx→0

f (x) = DNE limx→0

f (x) = DNE

limx→0

f (x) = DNE

limx→0−

f (x) = 0 limx→0−

f (x) = DNE

limx→0−

f (x) = 0

limx→0+

f (x) = 1

limx→0+

f (x) = DNE limx→0+

f (x) = DNE

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 25 / 33

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Section 1.6 – One-Sided Limits

limx→0

f (x) = DNE limx→0

f (x) = DNE

limx→0

f (x) = DNE

limx→0−

f (x) = 0 limx→0−

f (x) = DNE

limx→0−

f (x) = 0

limx→0+

f (x) = 1 limx→0+

f (x) =

DNE limx→0+

f (x) = DNE

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 25 / 33

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Section 1.6 – One-Sided Limits

limx→0

f (x) = DNE limx→0

f (x) = DNE

limx→0

f (x) = DNE

limx→0−

f (x) = 0 limx→0−

f (x) = DNE

limx→0−

f (x) = 0

limx→0+

f (x) = 1 limx→0+

f (x) = DNE

limx→0+

f (x) = DNE

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 25 / 33

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Section 1.6 – One-Sided Limits

limx→0

f (x) = DNE limx→0

f (x) = DNE limx→0

f (x) = DNE

limx→0−

f (x) = 0 limx→0−

f (x) = DNE

limx→0−

f (x) = 0

limx→0+

f (x) = 1 limx→0+

f (x) = DNE

limx→0+

f (x) = DNE

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 25 / 33

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Section 1.6 – One-Sided Limits

limx→0

f (x) = DNE limx→0

f (x) = DNE limx→0

f (x) = DNE

limx→0−

f (x) = 0 limx→0−

f (x) = DNE limx→0−

f (x) =

0

limx→0+

f (x) = 1 limx→0+

f (x) = DNE

limx→0+

f (x) = DNE

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 25 / 33

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Section 1.6 – One-Sided Limits

limx→0

f (x) = DNE limx→0

f (x) = DNE limx→0

f (x) = DNE

limx→0−

f (x) = 0 limx→0−

f (x) = DNE limx→0−

f (x) = 0

limx→0+

f (x) = 1 limx→0+

f (x) = DNE

limx→0+

f (x) = DNE

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 25 / 33

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Section 1.6 – One-Sided Limits

limx→0

f (x) = DNE limx→0

f (x) = DNE limx→0

f (x) = DNE

limx→0−

f (x) = 0 limx→0−

f (x) = DNE limx→0−

f (x) = 0

limx→0+

f (x) = 1 limx→0+

f (x) = DNE limx→0+

f (x) =

DNE

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 25 / 33

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Section 1.6 – One-Sided Limits

limx→0

f (x) = DNE limx→0

f (x) = DNE limx→0

f (x) = DNE

limx→0−

f (x) = 0 limx→0−

f (x) = DNE limx→0−

f (x) = 0

limx→0+

f (x) = 1 limx→0+

f (x) = DNE limx→0+

f (x) = DNE

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 25 / 33

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Section 1.6 – One-Sided Limits

One-sided limits are related to (two-sided) limits in the following way:

Theorem

A function f (x) has a limit as x approaches c if and only if it has left-handand right-hand limits there and these one-sided limits are equal:

limx→c

f (x) = L ⇐⇒ limx→c−

f (x) = L and limx→c+

f (x) = L.

The ”if and only if” (⇐⇒) in this theorem means:

if limx→c

f (x) = L, then both one-sided limits exist and are equal to L

if both one-sided limits exist and are equal to L, then limx→c

f (x) = L

The power of this theorem is in the second bullet. Let’s see it action.

Ken Keating (Kennesaw State University) Math 1190 – Calculus I Section 1.6 26 / 33

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Section 1.6 – One-Sided Limits

One-sided limits are related to (two-sided) limits in the following way:

Theorem

A function f (x) has a limit as x approaches c if and only if it has left-handand right-hand limits there and these one-sided limits are equal:

limx→c

f (x) = L ⇐⇒ limx→c−

f (x) = L and limx→c+

f (x) = L.

The ”if and only if” (⇐⇒) in this theorem means:

if limx→c

f (x) = L, then both one-sided limits exist and are equal to L

if both one-sided limits exist and are equal to L, then limx→c

f (x) = L

The power of this theorem is in the second bullet. Let’s see it action.

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Section 1.6 – One-Sided Limits

Theorem

limθ→0

sin θ

θ= 1 (θin radians)

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Section 1.6 – One-Sided Limits

To prove the theorem we are going to show that both the left-handand right-hand limits are equal to 1.

We’ll employ concepts from algebra, geometry, and trigonometry, aswell as calculus, in the proof.

Recall:

I area of a triangle =1

2bh

I area of a circle = πr2

I radians in a circle = 2π

I area of a sector =θ

2π· πr2 =

1

2r2θ

I tan θ =opposite

adjacent

I measured in radians, sin θ =x

r

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Section 1.6 – One-Sided Limits

Notes:the circle is a unit circle

0 < θ <π

2

area ∆OAP =1

2sin θ

area sector OAP =1

area ∆OAT =1

2tan θ

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Section 1.6 – One-Sided Limits

Proof.

area ∆OAP < area sector OAP < area ∆OAT

12 sin θ < 1

2θ <12 tan θ

divide each term by 12 sin θ (a positive #, so inequality signs unchanged)

1 < θsin θ <

1cos θ

take the reciprocal of each term (reverses the inequality signs)

1 > sin θθ > cos θ

Since limθ→0+ 1 = 1 and limθ→0+ cos θ = 1, by the Sandwich Theoremlimθ→0+

sin θθ = 1. Also, since sin θ and θ are both odd functions, sin θ

θ is an

even function, so limθ→0−sin θθ = limθ→0+

sin θθ . Thus, limθ→0

sin θθ = 1.

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Section 1.6 – One-Sided Limits

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Section 1.7 – Continuity

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Section 1.8 – Limits Involving Infinity

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