Evaluate the following integrals:
∫ x cos3 x2 sin x2 dx
Let cosx2 = t
Then d(cosx2) = dt
Since d(xⁿ) = nxⁿ⁻1 and d(cos x) = -sinx dx
dt = 2x (-sin x2) = -2x sin x2 dx
x sin x2dx =
hence ∫ x cos3 x2 sin x2 dx =
=