sin2x-tg x=0 sinx•(2cosx-1/cosx)=0 1) sinx=0 => x=πn 2) 2cos²x-1=0 => cosx=±1/√2 => x₁=±π/4+2πn, x₂=π±π/4+2πn x=π/4+(π/2)•n