\(\sin^4a+cos^4a+2sin^2a.cos^2a=\left(sin^2a+cos^2a\right)^2=1\)
Đúng 2
Bình luận (2)
\(\sin^4\alpha+2\cdot\sin^2\alpha\cdot\cos^2\alpha+\cos^4\alpha\)
\(=\left(\sin^2\alpha+\cos^2\alpha\right)^2\)
=1
Đúng 1
Bình luận (0)
