Thread: Max/Min Problem!

The Position function of an object moves in a straight line, Is:

s(t)= 1 + 2t - 8/(t^2+1)

Find the max andmin velocities for the object between 0<=x<=2

So what I tried was getting the 0's for the derivitive but i cant find any 0's! whats going on!!!!

The function is going to assume max/min in either an extreme point or one of the endpoints. What does your derivative look like?

Ok so i realized that the max min is when the acceleration is = 0 so i continued to find the second derivitive and it is equal to:

4t^3 +4t + 8

than i continued to find the zeros of that and the only zero is negative 1 which is confusing cause it doesnt fit in the domain..:S

OOOOO so do you use the endpoints since it cant occur inbetween?