Question

Найдите sinX^2+1/sinx^2,если sinx-1/sinx=-3

Answer 1

$sin^2x+frac{1}{sin^2x}=?\ (sinx-frac{1}{sinx})^2=sin^2x+frac{1}{sin^2x}-2=9\ sin^2x+frac{1}{sin^2x}=11$ Ответ  11