Question

Aflați valoarea expresiei E=$sin^{4} x+ cos^{4} x+2 sin^{2} x cos^{2} x$

Answer 1

$\sin^{4} x+ \cos^{4} x+2 \sin^{2} x \cos^{2} x=(\sin^2x+\cos^2x)^2=1^2=1$

Answer 2

E= (sin²x+cos²x)²
Conform formulei fundamentale a trigonometriei sin²α+cos²α=1
⇒E= (1)² ⇒ E=1