Sin^2(x-pi/4)=0,75 

sin (x - п\4) = -\+ sqr3\2 x-п\4 = п\3 + 2пn , x = 7п\12 +2пn x-п\4 = -п\3 +2пn,  x= - п\12  +2пn= п - п\12 +2пn = 11п\12 + 2пn