Question

[Nhók Lạnh Lùng]

giúp mik với

Answer 1

[Đặng Thị Cẩm Tú]

e k bk làm, e ms lp  7 ak a ^^

Answer 2

[nhung]

1)Ta có:\(\sin2\alpha=2\sin\alpha.\cos\alpha\)

\(1+\cos2\alpha=2\cos^2\alpha\)

\(\Rightarrow A=\frac{2\sin\alpha.\cos\alpha+\sin\alpha}{2\cos^2\alpha+\cos\alpha}=\frac{\sin\alpha\left(2\cos\alpha+1\right)}{\cos\alpha\left(2\cos\alpha+1\right)}=\frac{\sin\alpha}{\cos\alpha}=\tan\alpha\)