Transcript Slide 1

Homework

 Homework Assignment #5   Read Section 5.6

Page 341, Exercises: 1 – 19(Odd)

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

1.

Homework, Page 341

Water flows into an empty reservoir at the rate of 3000 + 5

t

gal/hr. What is the quantity of water in the reservoir after 5 hrs?

F

F

  0 5  

tdt

   3000

t

 5

t

2 2   5 0 15000  125 2

gal

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

3.

0.25

t

2

Homework, Page 341

A population of insects increases at a rate of 200 + 10

t

+ insects/day. Find the insect population after 3 days, assuming that there are 35 insects at

t

= 0.

I I

   0 5  0 5   

t

t

 0.25

t

2  0.25

t

2  

dt dt

  35 35  

  200

t

 10

t

2 2  0.25

t

3 3   3 0  647 insects

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

5.

Homework, Page 341

A factory produces bicycles at a rate of 95 + 0.1

produced from day 8 to day 21?

t

2 bicycles per week (

t

in weeks). How many bicycles were –

t B

B

  1 3  

t

2     95

t

 0.1

t

3 3 

t

2 2   1 3   9 2      1 2 

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

Homework, Page 341

7.

A cat falls from a tree (with zero initial velocity) at time

t

How far does the cat fall between

t

= 0.5 and

t

= 0. = 1 s? Use Galileo’s formula

v

(

t

) = –32

t

ft/s.

D

D

  1 0.5

 32

 16

t

16 2  1 0.5

  

12 ft

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

Homework, Page 341

Assume that a particle moves in a straight line with given velocity. Find the total displacement and total distance traveled over the time interval, and draw a motion diagram, with distance  y and time labels.

        0 5

     12

t

 4

t

2 2   5 0

 

2              t = 5, displacement = 10 t = 3, displacement = 18              0 5 

t dt

 26 ft        x

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

Homework, Page 341

Assume that a particle moves in a straight line with given velocity. Find the total displacement and total distance traveled over the time interval, and draw a motion diagram, with distance and time labels.

11.

t

 2 

 y  2 0.5

t

 2  1 

dt

  

t

 1  1 

t

  2 0.5

distance = 1, t = 2      2    2    0 m 1 0.5

 1 2  distance = 0.5, t = 1    2 0.5

t

 2  1

dt

 1 m  distance = 0, t = 0.5

   x

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

Homework, Page 341

13.

The rate (in liters per minute) at which water drains from a tank is recorded at half-minute intervals. Use the average of the left- and right endpoint approximation to estimate the amount of water drained in the first 3 min.

t 0

l/min 50

0.5

48

1.0

46

1.5

44

2.0

42

2.5

40

3.0

38

L N

R N

      135

l

 129

l

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

15. Let

 

Explain why 

t

1

t

2

Homework, Page 341

is the net change in velocity over 

t t

1 , 2  .

 

 

 24

t

t

2 2 3 ft/s .

The integral 

t

1

t

2 is the net change in velocity over 

t t

1 , 2  since, by the FTC, 

t

1

t

2  1 6  24

t

 3

t

2   12

t

2   

 

t

3

   

2

v t

1 , the net change in velocity.

 6 1

 216

 12 6     1 2 1 6  3   

   

3 205 ft/s 

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

Homework, Page 341

17.

The traffic flow past a certain point on a highway is

q

(

t

) = 3,000 + 2,000

t

+300

t

2 , where

t

is in hours and

t

= 0 is 8 AM. How many cars pass by during the time interval from 8 to 10 AM?

Q

Q

  0 2  

t

 300

t

2 

dt

       3000

t

 1000

t

2   100

t

3  10000 2 2   2 0 3  

 

3 

9, 200 cars

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

Homework, Page 341

19.

To encourage manufacturers to reduce pollution, a carbon tax on each ton of CO 2 released into the atmosphere has been proposed. To model the effects of such a tax, policymakers study the

marginal cost of abatement B

(

x

)

,

defined as the cost of increasing CO 2 reduction from x to x + 1 tons (in units of 10,000 tons – Figure 4). Which quantity is represented by  0 3

 

?

 0 3 represents the tens of thousands of dollars spent to reduce CO emissions by 2 30,000 tons

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

Jon Rogawski

Calculus, ET

First Edition Chapter 5:

The Integral

Section 5.6:

Substitution Method

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

When differentiating functions, we sometimes need to use the Chain Rule. We will now cover the Substitution Method of integration which is the Chain Rule “in reverse.”

x

2 sec 2  

dx

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

The Substitution Method is formally stated in Theorem 1.

Breaking down the integral as follows: We see that the antiderivative of

f

(

u

)

du

is

F

(

u

) +

C

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

Example, Page 349

Calculate

du

4.

u

 2

x

4  for the given function.

8

x

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

Example, Page 349

Write the integral in terms of

u

 1

dx u

x

2  1 and

du.

Then evaluate.

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

Example, Page 349

Write the integral in terms of

u

12.  

x

4

x

3  1  4

dx

,

u

x

4  1 and

du.

Then evaluate.

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

Example, Page 349

Write the integral in terms of

u

16. 

x

4

x

u

 4

x

 1 and

du.

Then evaluate.

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

Example, Page 349

Show that the integral is equal to a multiple of sin(

u

(x)) +

C

for an appropriate choice of

u

(

x

). 30. 

x

2 cos 

x

3  1 

dx

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

Example, Page 349

Evaluate the indefinite integral.

34. 

x

2 

x

3  1  3

dx

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

Example, Page 349

Evaluate the indefinite integral.

48. 

x

2

x

 1

7

dx

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

Example, Page 349

Evaluate the indefinite integral.

54. 

 

x dx

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company

Homework

 Homework Assignment #6   Review Section 5.6

Page 349, Exercises: 1 – 57(EOO)  Quiz next time

Rogawski Calculus Copyright © 2008 W. H. Freeman and Company