review+10+numbers18,+19,+20

18. __X 1.10 1.20 1.30 1.40__ F(x) 4.18 4.38 4.56 4.73 Let f be a function such that f "(x) <0 for all x in the closed interval [1,2], with selected values shown in table above. Which of the following must be true about f’(1.2)?
 * 1) f’(1.2) <0
 * 2) 0< f’(1.2)<1.6
 * 3) 1.6< f’(1.2)<1.8
 * 4) 1.8< f’(1.2)<2.0
 * 5) f’(1.2)>2.0

4.38-4.18 = __.2__ = 2 __4.56-4.38__ = __.18__ = 1.8 1.2-1.1 .1 1.3-1.2 .1 So the answer is 1.8< f’(1.2)<2, or letter d.


 * 1) Two particles start at the origin and move along the x-axis. For 0__<__t__<__10, their respective position functions are given by xsub1=sint and xsub2=e^(-2t)-1. For how many values of t do the particles have the same velocity?
 * 2) none
 * 3) one
 * 4) two
 * 5) three
 * 6) four

xsub1=sint xsub2=e^(-2t)-1 xsub1=cost xsub2=-2e^(-2t) cost=-2e^(-2t) Using a calculator, find the intersections from [0,10]. The graph shows three intersections, so the answer is d.

There is a minimum where the derivative of g, g’ or sin(t^2) goes from negative to positive. If you look at a graph, this point occurs at t=2.5066. There is a minimum at t=2.507, so the answer is letter e. Sarah Green
 * 1) If the function g is defined by g(x)=the integral from 0 to x of sin(t^2)dt on the closed interval –1__<__x__<__3, then g has a local minimum at x=
 * 2) 0
 * 3) 1.084
 * 4) 1.772
 * 5) 2.171
 * 6) 2.507