Question

A=(sin\(\alpha\)+cos\(\alpha\))² +(sin\(\alpha\)-cos\(\alpha\))²

B=sin⁶\(\alpha\)+cos⁶\(\alpha\)+3sin²\(\alpha\)+cos²\(\alpha\)

Answer 1

. mình ghi nhầm lớp 10, này là toán lớp 9 nha mb

Answer 2

a: \(=1+sin2a+1-sin2a=2\)

b: Sửa đề: \(B=sin^6a+cos^6a+3sin^2acos^2a\)

\(=\left(sin^2a+cos^2a\right)^3-3\cdot sin^2a\cdot cos^2a\cdot\left(sin^2a+cos^2a\right)+3sin^2a\cdot cos^2a\)

=1