Question

ПОМОГИТЕ!!!! sinx=cos2x

Answer 1

sinx=1-2sin^2x
2sin^2x-sinx+1=0
sinx=a
2a^2-a-1=0
D=(-1)^2-4×2×(-1)=3
x1=1+3/4=1 x2=1-3/4=-1/2
sinx=1 x=П/2+2пn
sinx=-1/2 x=(-1)^n×arcsin(-1/2)+Пn=(-1)^n+1×П/6+ Пn