Using the same substitution u = sin(x) enables us to do16 sin4(x) cos(x) dx = 16u4 du.In terms of u, we get

Making this substitution using16 sin2(x) cos3(x) dxgives us 16 sin2(x) (1 − sin2(x)) cos(x) dx = 16 sin2(x) cos(x) dx −  cos(x)  dx.

SOLUTION First we write cotangent in terms of sine and cosine:cot(x) dx = cos(x)sin(x) dx.This suggests that we should substitute u = sin(x), since then du =

∫e sin(x) cos(x)dx.

The integral 2𝜋 4xe−x2 dx can be done with the substitution u = and du = dx.

what is let u in Y = sec⁴ 0 - tan⁴ 0