# Math Help - velocity and acceleration

1. ## velocity and acceleration

Given that the acceleration vector is ,
the initial velocity is ,
and the initial position vector is , compute:
v(t) and r(t)
So far, i have v(t) = <sin(-t)+1, -cos(-t), 2t^2+1>
r(t) = <cos(-t)+t+1, t, (2/3)t^3+t+1>

But it's wrong, i still dun know what's wrong.

2. Originally Posted by zpwnchen
So far, i have v(t) = <sin(-t)+1, -cos(-t), 2t^2+1>
r(t) = <cos(-t)+t+1, t, (2/3)t^3+t+1>

But it's wrong, i still dun know what's wrong.
The j-component of v(t) is wrong (as is easily seen by substituting t = 0).

3. ## velocity and acceleration

gotcha! thanks.