Question

прошу вас помогите!срочно надо (

Answer 1

$sinxcdot cos2x+cosxcdot sin2x=frac{sqrt2}{2}\\sin3x=frac{sqrt2}{2}\\3x= left [ {{frac{pi}{4}+2pi n,; nin Z} atop {frac{3pi}{4}+2pi n,; nin Z}} right. ; ,; ; x= left [ {{frac{pi}{12}+frac{2pi n}{3},; nin Z} atop {frac{pi}{4}+frac{2pi n}{3},; nin Z}} right. ; ; x=left [ {{15^circ +120^circ n,; nin Z} atop {45^circ +120^circ n,; nin Z}} right. \\xin (20^circ ,70^circ ):; ; x=15^circ , ; x=45^circ ; .$