get confused with the wordy ones.......do I integrate this twice, then add coordinate values ?
many thanks
You do integrate twice. In the process of so doing, you should obtain two arbitrary constants of integration. If you plug in those two points (which, incidentally, can be done while integrating, sometimes, to save effort), you will be able to determine what those arbitrary constants of integration are. Make sense? What do you get?
Your second integration is incorrect - you're also integrating the +C from the first integration. You may also have a sign error on the first
$\displaystyle y' = -\dfrac{1}{2}\cos(2x) +c_1$
$\displaystyle y = -\dfrac{1}{4}\sin(2x) + c_1x + c_2$
where $\displaystyle c_1 \text{ and } c_2$ are constants to be found
edit: yes, it must be in radians. Nearly all trig calc is in radians as $\displaystyle \dfrac{d}{dx} \sin(x) = \cos(x)$ (and all the others) work only in radians