Integrate ∫cos2xdx.
Evaluate the given Integration:
Let,
I=∫cos2xdxcos2x=2cos2x-1⇒cos2x=1+cos2x2⇒I=∫dx2+∫cos2x2dx∵∫coscxdx=sincxc,∫dx=x⇒I=x2+sin2x4+C
Hence ∫cos2xdx =x2+sin2x4+C.