1) 4cosx-2√3=0
4cosx=2√3
cosx=√3/2
x=+-π/6+2πn
2) 10sinx+5√2=0
10sinx=-5√2
sinx=-√2/2
x1=-π/4+2πn
x2=-3π/4+2πn
3)tg(x/5)=√3
x/5=π/3+πn
x=5π/3+5πn
4)6cos(x-π/6)-3=0
cos(x-π/6)=1/2
x-π/6=+-π/3+2πn
x=+-π/3+π/6+2πn
x=+-π/2+2πn;n∈z
5)sin(π+x)+2cos(π/2+x)=3
-sinx-2sinx=3
-3sinx=3
sinx=-1
x=-π/2+2πn;n∈z