1.
tg(x-π/4)=√3
x-π/4=π/3+πn
x=π/3+π/4+πn
x=7π/12+πn.
2.
cosx=-1
x=π+2πn.
3.
sin2x=1
2x=π/2+2πn
x=π/4+πn.
4.
cos(x+π/4)=0
x+π/4=π/2+πn
x=π/2-π/4+πn
x=π/4+πn.
5.
tg3x=0
3x=πn
x=πn/3.
6.
cosx=√2/2
x=+/-π/4+2πn.
7.
√2*cosx-1=0
√2*cosx=1
cosx=1/√2
cosx=√2/2
x=+/-π/4+2πn.