3 cos^2x-7sinx-5=0
3-3sin^2x-7sinx-5=0
3sin^2x+7sinx+2=0
sinx=-1/3
x=-arcsin(1/3)+2Пk
x=arcsin(1/3)+2Пk-П
3 cos^2x-7sinx-5=0
3-3sin^2x-7sinx-5=0
3sin^2x+7sinx+2=0
sinx=-1/3
x=-arcsin(1/3)+2Пk
x=arcsin(1/3)+2Пk-П