Evaluate:
Show that:
Let I = Put x = cos2 θ, θ dx = 2 cos θ (– sin θ) dθ = – 2 sin θ cos θ dθ = – sin 2θ dθWhen x = 0, When x = 1, cos2 θ = 1 ⇒ θ = 0
By using the properties of definite integrals, evaluate the following integral: