Question

решите уравнение
sin x2 * sin 3x2 = 12

Answer 1

1/2*(cosx-cos2x)=1/2
cosx-cos2x=1
cosx-2cos²x+1-1=0
cosx-2cos²x=0
cosx*(1-2cosx(=0
cosx=0⇒x=π/2+πn,n∈z
cosx=1/2⇒x=+-π/3+2πn,n∈z