The position s(t) of an object moving is in a straight line is given:
s(t)=2t^4-5t^3+t-3
a. Find object velocity v(t) and acceleration a(t).
b. find all times t when the acceleration is 0.
Your equation for velocity seems correct, I cannot read your one for acceleration though, could you take a minute and put it in the correct latex code.
Latex Tutorial