Question

(1/cos^2x*cos^2x-sin^2x)/sin^2x  упростите

Answer 1

$left(frac{1}{cos^2x}cdot cos^2x-sin^2xright):sin^2x=frac{1-sin^2x}{sin^2x}=frac{cos^2x}{sin^2x}=left(frac{sinx}{cosx}right)^2=tg^2x$