homework homework assignment #8 read section 5.8 page 355, exercises: 1 – 69(eoo) quiz next time...
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Homework
Homework Assignment #8 Read Section 5.8 Page 355, Exercises: 1 – 69(EOO) Quiz next time
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
Example, Page 355Evaluate the definite integral.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
2
1
11. dx
x
22
1 1
2
1
1ln ln 2 ln1 ln 2
1ln 2
dx xx
dxx
Example, Page 355Evaluate the definite integral.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
2
15. e
e dtt
2 2
2
2
1ln
ln ln 1 2 1
11
ee
e e
e
e
dt tt
e e
dtt
x
y
Example, Page 355Evaluate the definite integral.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
23
2 2
19.
1dx
x x
2 213 3
2 22
23
2 2
1sec
6 3 61
1
61
dx xx x
dxx x
Example, Page 355Evaluate the definite integral.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
2
0 2
113.
4dx
x
2
2 2 2 10 0 0 22
2 0
1 1
2
0 2
111 1 1 14 tan
14 4 4 214 441 1
tan 1 tan 0 04 4 4 16
1
4 16
xdx dx dx
xx x
dxx
Example, Page 355Evaluate the indefinite integral.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
217.
25 4
dt
t
1
2 22
1
2
11 1 25 sin
1 5 5 5425 4 125 4 255
1 2sin
5 525 4
dtdt dt tC
t tt
dt tC
t
Example, Page 355Evaluate the indefinite integral.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
2
121.
1
x dx
x
2
2 2 2
21 1
2 2
1 2
2
11 , 2 ,
21 1 1
1 1 1sin sin
12 21 1 2
1sin 1
1
x dx xdx dx du duu x x xdx
dxx x x
xdx dx du xx C x C
ux x
x dxx x C
x
Example, Page 355Evaluate the indefinite integral.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
1
2
tan25.
1
xdx
x
12 2
1 221
2
121
2
1tan , ,
1 1
tantan
1 2
tantan
1
du dxu x du
dx x x
xdx uudu C x C
x
xdxx C
x
Example, Page 355Evaluate the definite integral.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
4log 3
029. 4x dx
4 4
4
4
log 3 log 3 0log 3
0
0
log 3
0
4 4 4 3 1 24
ln 4 ln 4 ln 4 ln 4 ln 4 ln 4
24
ln 4
xx
x
dx
dx
Example, Page 355Evaluate the integral using methods covered so far.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
33. 2xe dx
2 2 2
2 2
x x x
x x
e dx e dx dx e x C
e dx e x C
Example, Page 355Evaluate the integral using methods covered so far.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
437. 1xe dx
4 4
4 4
4 4
1 4 , 4,4
1 1 1
4 4 4
11
4
x x
x u u x
x x
du due dx e dx dx u x dx
dx
e dx dx e du x C e x C e x C
e dx e x C
Example, Page 355Evaluate the integral using methods covered so far.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
241.
1 16
dx
x
1 1
2 2
1
2
4 , 4,4
1 1 1sin sin 4
4 4 41 16 1
1sin 4
41 16
du duu x dx
dxdx du
u C x Cx u
dxx C
x
Example, Page 355Evaluate the integral using methods covered so far.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
1045. 7 xe dx
10
10
10 , 1010
17 7 7
10 10
7 10 710
ux u
xx
du duu x dx
dx
ee dx dx e du x C
ee dx x C
Example, Page 355Evaluate the integral using methods covered so far.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
2449. xxe dx
2 2
2 2
2
4 4
4 4
4 , 8 ,8
1 1 1
8 8 8
1
8
x u u x
x x
du duu x x xdx
dx
xe dx e du e C e C
xe dx e C
Example, Page 355Evaluate the integral using methods covered so far.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
53. 2 4
dx
x
2 4, 2,2
1 1 1ln ln 2 4
2 4 2 2 2
1ln 2 4
2 4 2
du duu x dx
dxdx du
u C x Cx u
dxx C
x
Example, Page 355Evaluate the integral using methods covered so far.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
57. tan 4 1x dx
4 1, 4,4
cos1 1 sin
tan 4 1 tan4 4 cos sin
1 sin 1 1 1ln ln cos
4 cos 4 4 41
ln cos 4 14
1tan 4 1 ln cos 4 1
4
du duu x dx
dxv u
ux dx udu du dv
u udu
u dvdu v C u C
u v
x C
x dx x C
Example, Page 355Evaluate the indefinite integral.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
4ln 561.
xdx
x
22
2
4ln 5 4ln 5 1ln , ,
4 ln 54 5 4 ln 2 ln ln
2
4ln 52 ln ln
x x du dxdx dx dx u x du
x x x dx x x
x dx udx udu x C x x C
x x
xdx x x C
x
Example, Page 355Evaluate the indefinite integral.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
ln ln65.
ln
xdx
x x
22
2
ln ln 1ln ln , ,
ln ln lnln ln 1
ln lnln 2 2
ln ln 1ln ln
ln 2
x du dxdx u x du
x x dx x x x xx u
dx udu C x Cx x
xdx x C
x x
Example, Page 355Evaluate the indefinite integral.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
sin69. cos 3 xx dx
sin
sinsin
sinsin
cos 3 sin , cos , cos
3 3cos 3 3
ln 3 ln 3
3cos 3
ln 3
x
u xx u
xx
dux dx u x x du xdx
dx
x dx du C C
x dx C
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
Chapter 5: The IntegralSection 5.8: Exponential Growth and Decay
Jon Rogawski
Calculus, ETFirst Edition
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
There are many examples in biology, physics, and economics where“populations “ grow or decay at exponential rates. The general formula describing this growth or decay is:
If k > 0, then the population is growing and if k < 0, the population is decaying.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
The e. coli bacteria shown in Figure 1 multiply exponentially. That is why, within hours of ingesting contaminated food or drink, a person becomes severely ill from this bacteria.
As can be extrapolated from the graph in Figure 2, in less than 24hours, an initial population of 1,000 bacteria would have grown to over 1,600,000, more than enough to affect the healthiest person.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
If a quantity is changing in proportion to the amount currently present, then it is increasing/decreasing exponentially
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
The rate a which penicillin leaves the bloodstream is proportional to the amount present. If an initial amount of 450 mg is administered and 50 mg remains after seven hours, what is the decay constant? At what time after the injection, did 200 mg remain?
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
A frequently asked question is: “When will this process produce twice the original amount?” This question can be answered bysolving 2 = 1 ekt for t.
Example, Page 3662. A quantity P obeys exponential growth law P = e5t (t in years).
(a) At what time t is P = 10?
(b) At what time t is P = 20?
(c) What is the doubling time for P?
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
Figure 4 shows a graph of the number of bachelor’s degrees awardedin physics each year from 1955 to about 1978. The figure is markedto emphasize the doubling that took place about every seven years.
Rogawski CalculusCopyright © 2008 W. H. Freeman and Company
If the number of microscopic plants shown in Figure 5 doubles every30 hours, what is the k value we should use?