Question

Express the trigonometric ratio tan A in terms of sec A.

Answer 1

Since, $se{c}^{2}A-ta{n}^{2}A=1$
$\Rightarrow ta{n}^{2}A=se{c}^{2}A-1$
$\Rightarrow tanA=\pm \sqrt{se{c}^{2}A-1}$