7. Find

a) dx d ( a x tan(u)du)

b) dx d ( 1 x 2 1+2t dt)

8. Use integrals and the graphs of f(x)=1+x and g(x)=3x to determine the area between the graphs of f and g for 0x3 .

9. A robot has been programmed so that when it starts to move, its velocity after t seconds will be 3t 2 feet/second.

(a) How far will the robot travel during its first 4 seconds of movement?

(b) How far will the robot travel during its next 4 seconds of movement?

(c) How many seconds before the robot is 729 feet from its starting place?