Sin^4+cos^4=sin2x+1,5

Question

Sin^4+cos^4=sin2x+1,5

Answer 1

1-((sin2x)^2)/2=sin2x+1,5

Answer 2

(sin^2 +cos^2)^2    -2sinxcos x = sin 2x+1.5

1-sin2x -sin 2x -1.5 = 0

-2sin2x =1/2

sin2x= -1/4

2x =(-1)^n *(-arcsin 1/4) +pin

x = (-1)^(n+1)*(arcsin1/4)*1/2 +pin/2