Question

Решите уравнение 8sin^2x-6sin x-5+0

Answer 1

8sin^2x-6sin x-5=0
sinx=a
8a²-6a-5=0
D=36+160=196
a1=(6-14)/16=-12/16=-0,75⇒sinx=-0,75⇒x=(-1)^n+1 *arcsin0,75+πn
a2=(6+14)/16=20/16=5/4∉[-1;1]