Originally Posted by

**scorpion007** Hi, im having trouble with some questions, here's one, i will post more as i run into more problems.

The acceleration of an object, $\displaystyle a m/s^2$ moving in a line at t seconds is given by $\displaystyle a = sin(2t)$ if the object has an initial velocity of 4 m/s then v is equal to?

Now you'd think i would just have to integrate a and find the c constant, so i got: $\displaystyle -\frac{1}{2}\cos{2t}+\frac{9}{2}$

but the answer was this:

$\displaystyle \int_{0}^{t} sin(2x)dx + 4$

can someone explain why this is correct?