Math Help - Integration question ( really quick)

1. Integration question ( really quick)

Is the integral of sin(x/2) = -cos(x/2)

2. $\displaystyle\int \sin\frac{x}{2}~dx = -2\cos\frac{x}{2}+C$

But why?

3. Haha I need it for another problem, But thank you very much.

4. That was not what pickslides meant. Do you understand why the integral is $-2 cos\frac{x}{2}+ C$ rather than $cos \frac{x}{2}$?