Question

Sinx^4+cosx^4=sinXcosx

Answer 1

sinx^4+2Sinx^2*cosx^2+cosx^4-2sinx^2*cosx^2=sinx*cosx

(sinx^2+cosx^2)^2-2sinx^2cosx^2=sinx*cosx

1-sinx*cosx-2sinx^2*cosx^2=0

t=sinx*cosx

1-t-2t^2=0

D=1+8=9

t1=-1

t 2=1/2

дальше сам,ок?