Question

If $x$ = $\sqrt{a}tan\alpha$ and $y$ = $\sqrt{a}sec\alpha$. The value of $y^2$ – $x^2$ is ___.

Answer 1

$x$ = $\sqrt{a}tan\alpha$ and $y$ = $\sqrt{a}sec\alpha$

$x^2$ = $ata{n}^2\alpha$ and $y^2$ = $ase{c}^2\alpha$ $\Rightarrow$ $y^2$ - $x^2$ = $a(se{c}^2\alpha -ta{n}^2\alpha )$ = $a$