Question

Решите уравнение sin^2x+sinx-2=0

Answer 1

$sin^2x+sinx-2=0 \sinx=y, y in [-1;1] \y^2+y-2=0 \D=1+8=9=3^2 \y_1= frac{-1+3}{2} =1 \y_2= frac{-1-3}{2} notin [-1;1] \sinx=1 \x= frac{pi}{2}+2pi n, n in Z$