Câu 2 : VT = $\frac{sin^2\alpha }{cos^2\beta } + \frac{sin^2\beta\times cos^2\alpha }{cos^2\beta } = \frac{sin^2\alpha + sin^2\beta (1 - sin^2\alpha )}{cos^2\beta }= \frac{sin^2\alpha (1 - sin^2\beta ) + sin^2\beta }{cos^2\beta } = \frac{sin^2\alpha \times cos^2\beta + sin^2\beta }{cos^2\beta } = sin^2\alpha + tan^2\beta = VP$
Câu 2 : VT = $\frac{sin^2\alpha }{cos^2\beta } + \frac{sin^2\beta\times cos^2\alpha }{cos^2\beta } = \frac{sin^2\alpha + sin^2\beta (1 - sin^2\alpha )}{cos^2\beta }= \frac{sin^2\alpha (1 - sin^2\beta ) + sin^2\beta }{cos^2\beta }$
Câu 2 : VT = $\frac{sin^2\alpha }{cos^2\beta } + \frac{sin^2\beta\times cos^2\alpha }{cos^2\beta } = \frac{sin^2\alpha + sin^2\beta (1 - sin^2\alpha )}{cos^2\beta }= \frac{sin^2\alpha (1 - sin^2\beta ) + sin^2\beta }{cos^2\beta }
= \frac{sin^2\alpha \times cos^2\beta + sin^2\beta }{cos^2\beta } = sin^2\alpha + tan^2\beta = VP$