Question

Cos^2x - sin^2x = sqrt или корень 2

Answer 1

(1-sin^2(x))-sin^2(x)=sqrt(2)

1-2sin^2(x)=sqrt(2)

-2sin^2(x)=sqrt(2)-1

sin^2(x)=(sqrt(2)-1)/2

sinx=sqrt((sqrt(2)-1)/2)

x=(-1)^k*arcsin (sqrt((sqrt(2)-1)/2)) + p*k, k=Z