sin2x=√2sin(pi/2+х) 2sinxcosx=√2cosx 2sinxcosx-√2cosx=0 cosx(2sinx-√2)=0 cosx=0 x=pi/2+pik, k∈Z sinx=√2/2 x=pi/4+2pik, k∈Z; x=3pi/4+2pik, k∈Z