know the double angle formula? cos 2x = ... ?
in terms of cos^2 x
No i dont
ok, its good to know all variations of cos 2x formula I will write the 3 most important ones for you \(\Large \cos 2x = \cos^2 x - \sin^2 x\) \(\Large \cos 2x = 2\cos^2 x - 1\) \(\Large \cos 2x = 1-2\sin^2 x \)
we need to use the 2nd one for our problem try to get expression for cos^2 x from it
oh alright we are allowed to have a formula page. It says cos^2 x =1+cos2/2
exactly, that you'll get from the 2nd formula, just plug that into your integral!
Alright this wasnt so bad! Thank you :)
thanks cant forget the c.