hasil penyelesaian dari ∫ cot x sec^2x

int (cosx/sinx)(1/cos²x) dx
= int 1/(sinx cosx) dx
= int 2/sin(2x) dx
u = 2x → du = 2 dx → dx = (1/2) du
= int 1/sinu du
v = tan(u/2) → du = 2/(1 + u²) dx
= int 1/v dv
= ln│v│ + c
= ln│tanx│ + c, atau
= ln(sinx) - ln(cosx) + c