Question

Помогите решить, найти неопределенный интеграл (cos2x)/cos^2xsin^2x dx

Answer 1

$\int \frac{cos2x}{cos^2 x*sin^2x}dx = \int \frac{cos^2x-sin^2x}{cos^2 x*sin^2x}dx = \int \frac{cos^2x}{cos^2 x*sin^2x}dx -\int \frac{sin^2x}{cos^2 x*sin^2x}dx =\\\\ \int \frac{dx}{sin^2x} -\int \frac{dx}{cos^2 x}=-ctgx-tgx+C=-( \frac{cosx}{sinx} + \frac{sinx}{cosx} )+C=\\\\ =-( \frac{cos^2x+sin^2x}{sinxcosx})+C=-\frac{1}{sinxcosx}+C$