im3l1.1 introduction to functions - mr santowski's math...
TRANSCRIPT
IM3 -‐ Lesson 1: Introduction to Functions Unit 1 – Basics of Function
A. Lesson Context
BIG PICTURE of this UNIT:
• What do we mean by the term “function” • How do we work with the concept of “functions” given our prior experience with
linear and exponential relations from IM2? • How do we apply the function concept to linear systems?
CONTEXT of this LESSON:
Where we’ve been In your video HW, you were introduced to the concept of relations an functions
Where we are How do we work with function notations & the multiple representations of functions, both in a mathematical & a contextual context
Where we are heading How do we apply the concept of “functions” to linear & exponential relations
B. Lesson Objectives a. Find the domain and range of a relation. b. Identify if a relation is a function or not. c. Work with function notation & evaluating functions. d. Work with function notation in application based problems.
C. Fast Five (Skills Review Focus)
a. Factor
b. Evaluate
c. Factor
d. Evaluate
e. Solve for x. f. Solve .
g. Determine the equation of the axis of
symmetry of
h. Determine the optimal point of
IM3 -‐ Lesson 1: Introduction to Functions Unit 1 – Basics of Function
D. NEW CONCEPT for IM3: Function Basics (Summary from Videos)
a. Relations: i. A "relation" is just a relationship between sets of information;
ii. A relation refers to a set of input and output values, usually represented in ordered pairs
iii. A relation is simply a set of ordered pairs.
b. Functions: i. A function is a "well-‐behaved" relation When we say that a function is "a well-‐behaved
relation", we mean that, given a starting point, we know exactly where to go; given an x, we get
only and exactly one y.
ii. Function is a relation in which each element of the domain is paired with exactly one element of
the range.
iii. A function is a set of ordered pairs in which each x-‐element has only ONE y-‐element associated
with it.
iv. A function is a rule that takes an input, does something to it, and gives a unique corresponding
output.
c. Notations: i. Rather than writing linear equations in the typical y = mx + b format, we will now write them in
function notation as f(x) = mx + b where “f” simply refers to the function name and the x
refers to the input and f(x) (or y) refers to the output
ii. Evaluate if f(x) = 2x + 4, then we can evaluate f(3) as ……
iii. Solve if f(x) = 2x + 4, then we can solve 12 = f(x) as …..
d. Understanding Domain and Range:
i. The set of all the starting points is called "the domain" and the set of all the ending points is
called "the range."
ii. The domain is what you start with; the range is what you end up with.
iii. The domain is the x's; the range is the y's
IM3 -‐ Lesson 1: Introduction to Functions Unit 1 – Basics of Function
D. NEW CONCEPT for IM3: Function Basics (Summary from Videos) e. Understanding the Notation
So the symbols that make up this notation of f(3) = 7 communicate INFORMATION
f 3 7
The information being communicated by these “symbols” can also be PRESENTED in ALTERNATE WAYS:
(i) op (ii) m (iii) g
To show the RELATIONSHIP between the INPUT VALUES & OUTPUT VALUES, we can use EQUATIONS:
IM3 -‐ Lesson 1: Introduction to Functions Unit 1 – Basics of Function
E. Working with Functions and Relations a. Example 1
b. Example 2
c. Example 3
IM3 -‐ Lesson 1: Introduction to Functions Unit 1 – Basics of Function
F. Further Examples:
IM3 -‐ Lesson 1: Introduction to Functions Unit 1 – Basics of Function
G. Further Examples
IM3 -‐ Lesson 1: Introduction to Functions Unit 1 – Basics of Function
H. Application of Functions
Mr. S. went on a two day hiking and camping adventure with his son Andrew. Here is a function y = d(t) which represents a Distance-‐Time graph for Mr. S’s and Andrew’s hike. The x axis (the independent variable) is time in hours since we left our campsite and the y-‐axis represents the distance from our campsite.
d. Evaluate d(0) and interpret what this point represents.
e. Evaluate d(5) and interpret what this point represents.
f. Evaluate d(15) and interpret what this point represents.
g. For what values of t does d(t) = 8? Interpret your answer in the context of the problem.
h. For what values of t does d(t) = 12? Interpret your answer in the context of the problem.
i. For what values of t does d(t) = 0? Interpret your answer in the context of the problem.
IM3 -‐ Lesson 1: Introduction to Functions Unit 1 – Basics of Function
j. For what values of t does d(t) > 10? Interpret your answer in the context of the problem.
k. For what values of t does d(t) < 2? Interpret your answer in the context of the problem.
l. What is the domain of the function y = d(t)? Interpret your answer in the context of the
problem.
m. What is the range of the function y = d(t)? Interpret your answer in the context of the problem.
n. What is the slope of the function on the interval 0 < t < 6? Interpret your answer in the context
of the problem.
o. What is the slope of the function on the interval 6 < t < 13? Interpret your answer in the context
of the problem.
p. What is our average speed in the first 12 hours of our hike?
q. What is our average speed in the final 6 hours of our hike?
r. How far did we hike?
s. Write an equation that represents the first 13 hours of our hike .
t. Write an equation that represents the complete hiking trip.
I. HOMEWORK/Classwork from the Nelson 11, Chap 1.1 pg10 -‐ 12, complete Q1,3,4,6,7,8,10,13,15