Sin^4x+cos^4x=sin^22x-1/2

Question

Sin^4x+cos^4x=sin^22x-1/2

Answer 1

(1-cos2x)²/4+(1+cos2x)²/4=-cos²x/2
1-2cos2x+cos²2x+1+2cos2x+cos²2x=-2cos²2x
2+2cos²2x+2cos²2x=0
4cos²x=-2
нет решения