1.ctg(pi/4-x/3)=√3/3, x≠3/4pi+3piK
pi/4-x/3=pi/3
3pi-4x=4pi+12piK
-4x=4pi-3pi+12piK
x=-pi/4-3piK
x=11pi/4+3piK
2.6-6sin^2x+5sinx-7=0
-1-6sin^2x+5sinx=0
1-6t^2+5t=0
t1=1/2
t2=1/3
sinx=1/2:x=pi/6+2piK
sinx=1/3:x=5pi/6+2piK
x=arcsin(1/3)+2piK
x=-arcsin(1/3)+pi+2piK