Question

A particle moves along the x-axis with the velocity at time t=>0 given by v(t)=t^2-3 cos(t). If the particle is at the origin when t=0, its position at the time when v=0, x=??
a. 5.276
b. 334.965
c. 15.276
d. 6.682
e. 2.670

Answer 1

if v(t) = t^2 - 3cos(t)
then
s(t) = (1/3)t^3 - 3sin(t) + c
given : when t = 0 , s(0) = 0
0 = 0 - 3sin0 + c
c = 0

so when v = 0
0 = t^2 - 3cos(t)
using Wolfram, I got
t = 1.13062
where does x enter the picture, your function was defined in terms of t

http://www.wolframalpha.com/input/?i=0+%3D+t%5E2+-+3cos%28t%29+%2C+t%E2%89%A50