Sinx cos45° + cosx sin45° = cos17°cos13° - sin17°sin13°

Question

Sinx cos45° + cosx sin45° = cos17°cos13° - sin17°sin13°

Answer 1

По формулам  получаем:
sin(x+45)=cos(17+13)
sin(x+45)=cos30
sin(x+45)=sqrt3/2
x+45=(-1)^n*arccos(sqrt3/2)+pin
x+pi/4=(-1)^n*pi/3+pin
x=(-1)^n*pi/3-pi/4+pin