Упростите выражение:
sin^2x+cos^4x-0,75

sin²x = 1 - cos²x

(a - b)² = a² - 2ab + b²

cos(2x) = 2cos²x - 1

[tex]sin^2x+cos^4x-0,75=1-cos^2x+cos^4x-0,75=\\\\=cos^4x-cos^2x+\frac{1}{4}=(cos^2x)^2-2\cdot \frac{1}{2}\cdot cos^2x+(\frac{1}{2})^2=\\\\=(cos^2x-\frac{1}{2})^2=(\frac{1}{2}(2cos^2x-1))^2=(\frac{1}{2}cos2x)^2=\frac{1}{4}cos^22x[/tex]