Cho anpha và bêta là hai góc phụ nhau. Hệ thức nào sau đây không đúng

$A.{\sin }^2\alpha +{\cos }^2\alpha =1$

$\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}B.\cot \alpha .\tan \alpha =1$

$\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}C.\tan \alpha =\frac{\sin \alpha }{\cos \alpha }$

$\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}\hspace{0.17em}D.\sin \alpha =\cos \left({90}^0-\beta \right)$