1) 2sinX = - 1

3) tg ([tex] \frac{ \pi }{2} - x)[/tex] = - 1

1) 2sinX = - 1sinx = - 1/2x = (-1)^n*arcsin(-1/2) + πn, n∈zx = (-1)^(n+1)*arcsin(1/2) + πn, n∈zx = (-1)^(n+1)*(π/6)+ πn, n∈z3) tg (π/2 - x)  = - 1ctgx = - 1x = - π/4 = πk, k∈Z