Question

Evaluate the integral. (Remember to use ln(|u|) where appropriate.)

cot^3(3x) dx

Answer 1

cot^3 = cot cot^2

= cot (csc^2 - 1)
= cot csc^2 - cot
= cot csc^2 - cos/sin
Now your way should be clear, since

d/dx(cot) = -csc^2
d/dx(log sin) = cos/sin