1-sin2a=ctg2a*sin2a упростить

sin^2(a)-2sinacosa+cos^(a)=cos2a/sin2a*sin2a cos^2(a)+sin^2(a)-sin2a=cos2a cos^2(a)+sin^(a)-sin2a-cos^2(a)+sin^2(a)=0 2sin^2(a)-sin2a=0 2sin^2(a)-2sinacosa=0 2sina(sina-cosa)=0 1)2sina=0                           2)sina-cosa=0    делит на sina sina=0                                   tga-1=0                         a=пn                                     tga=1                                             х=п/4+пn