sin(x-π/4)=√2/2
x-pi/4=pi/4+2pik
x=pi/4+pi/4+2pik
x=pi/2+2pik
x-pi/4=3pi/4+2pik
x=3pi/4+pi/4+2pik
x=pi+2pik
+отбор корней: pi/2, pi
sin(x-π/4)=√2/2
x-pi/4=pi/4+2pik
x=pi/4+pi/4+2pik
x=pi/2+2pik
x-pi/4=3pi/4+2pik
x=3pi/4+pi/4+2pik
x=pi+2pik
+отбор корней: pi/2, pi