Sinx+2=0

sin2x=-√3/2

2cosx-√2=0

cos5x=0

√3tg2x+1=0

1) sinx=-2

x = (-1) ⁿarcsin (-2) + πn, n∈Z

2) sin2x=-√3/2

x = (-1) ⁿ arcsin (-√3/2) + πn, n∈Z

x = - ((-1) ⁿ * π/3) + πn, n∈Z

3) 2cosx=√2

cosx=√2/2

x=+-arccos (√2/2) + 2πn, n∈Z

x=+-π/4+2πn, n∈Z

4) cos5x=0

5x=π/2+πn, n∈Z

x=π/10+πn/5, n∈Z

5) tg2x=-1/√3

x=-arctg (1/√3) + πn, n∈Z

2x=-π/6++πn, n∈Z

x=-π/12+πn/2, n∈Z