Question

Упростите выражение:
(1/sin^2a)+(1/cos^2a)

Answer 1

$\frac{1}{sin ^{2} \alpha }+ \frac{1}{cos ^{2} \alpha }= \frac{cos ^{2} \alpha +sin ^{2} \alpha }{sin ^{2} \alpha\cos ^{2} \alpha }= \frac{4}{sin ^{2}2 \alpha }$