AP Calculus

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AP Calculus

Riemann Sums and Trapezoidal Rule

Name: _____________________

1. By reading values from the given graph of f, use five rectangles to find: a. a lower estimate for the area under the given graph b. an upper estimate for the area under the given graph of f from x = 0 to x = 10. Sketch the rectangles of f from x = 0 to x = 10. Sketch the rectangles that y you use.





 x that you use.





 y x

             





           graph of f from x = 0 to x = 10. Sketch the rectangles

 that you use.



 y

















             



           d. an estimate using trapezoids for the area under the

 trapezoids that you use.

 y









 

 



 

 





 

             





        x

                





        x

  

________________________________________________________________________________________________

 f ( x )









1

1

2. Graph the function

 x

2 a. Right endpoints

 three approximating rectangles and taking the sample points to be:



 b. Left endpoints c. Midpoints











 d. Trapezoids

 

 

 

 

 

________________________________________________________________________________________________

3. Coal gas is produced at a gasworks. Pollutants are removed by screens which become less efficient as time goes on. Measurements are made every two months showing the rate at which pollutants escape..

Time (months) 0

Rate (tons/month) 5

2

8

4 6

13 20

Find the amount of pollutants that escape using a: a. lower estimate b. upper estimate

_______________________________________________________________________________________________

4. The following table gives the emissions, E, of nitrogen oxides in millions of metric tons per year in the US. Let t be the number of years since 1940 and E

 f ( t ) .

Year

E

1940

6.9

1950

9.4

1960

13.0

1970

18.5

1980

20.9

1990

19.6

Estimate the amount of nitrogen oxides emitted from 1940 to 1990 using five subintervals and: a. a left Riemann sum b. a right Riemann sum. c. a trapezoidal approximation

________________________________________________________________________________________________

5. Oil is leaking out of a tanker damaged at sea. The damage to the tanker is worsening as evidenced by the increased leakage each hour, recorded in the table below.

Time (hours) 0

Leakage (gal/hr) 50

1

70

3 6 8

136 369 720 a. Give an upper estimate for the total quantity of oil that has escaped after 8 hours. b. Give a lower estimate for the total quantity of oil that has escaped after 8 hours.

6. The graph of the velocity v(t), in ft/sec, of a bicycle racing on a straight road, for a. Approximate the value of the distance the bicycle traveled using a

 y

right Riemann sum with the five subintervals indicated by the data in the graph. Show your setup.





0

 t

60 , is shown below. b. Is this numerical approximation less than the actual distance the bicycle traveled? Explain your reasoning.











 c. Approximate the value of the distance the bicycle traveled using a left Riemann sum with the five subintervals indicated by the data in the graph. Show your setup.





          

________________________________________________________________________________________________

 x

7. Ben Travlen rides a unicycle back and forth along a straight east-west track. The twice differentiable function models Ben’s position on the track, measured in meters from the western end of the track, at time

B t , measured in seconds from the start of the ride. The table gives values for Ben’s velocity, v ( t ) , measured in meters per second, at selected times t .

(A) Use the data in the table to approximate Ben’s acceleration at time t

5 seconds. Indicate units of measure.

(B) Approximate the distance Ben traveled for the first 60 seconds using a left Riemann sum with the subintervals indicated by the data in the table.

________________________________________________________________________________________________

8. The table shows selected values for a twice differentiable function f. x f(x)

-3

5

-2

3

-1

2

0

-1

1

1

2

-4

3

-7

Estimate the area under the graph of f using a midpoint Riemann sum with 3 subintervals of equal length.

________________________________________________________________________________________________

9. The function R that approximates the rate that water is being pumped into a reservoir, in gallons per minute, is continuous on the closed interval [ 0 , 6 ] and has the values given in the table. The trapezoidal approximation for the amount of water pumped for the first 6 hours found with 3 subintervals of equal length is 52. What is the value of k ? t (minutes) 0

Rate 4

(gal/min)

2

K

4

8

6

12

(A) 2 (B) 6 (C) 7 (D) 10 (E) 14

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10. The graph shows the rate of bamboo growth bamboo is 60 cm tall at time t

10 g ( t ) in centimeters (cm) per day over a 20 day period. If the

days, approximately how tall is it at t

20 days?

(A) 25 cm

(B) 64 cm

(C) 70 cm

(D) 82 cm

(E) 100 cm

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