Question

2cos2x-1=cosx-2sin2x;​

Answer 1

Ответ:

cosX=1

Пошаговое объяснение:

2 cos^2 X - 1 = cosX -2sin^X

2 cos^2 X-(sin^2 X + cos^2 X)=cosX -2sin^2X

"cos^2X-sin^2X-cos^2X=cosX-2sin^2 X

cos^2X-cosX=sin^2X-2sin^2 X

cos^2X-cosX=-sin^2X

cos^2X+sin^2X=cosX

cosX=1