Question

evaluate the integral:
∫cos²x on (0, π/4)

Answer 1

Integral of cos^2 is

1/2 ( x +sinxcosx )

So plug in for your limits of integration and solve!

Answer 2

you need power reduction formula

Answer 3

\[\cos^2x=\frac{1+\cos(2x)}{2}\]

Answer 4

this is what DS did above i believe then he just took the double angle and use that