Question

(sec a - tan a)/(sec a + tan a) = 1-2 sec a tan a + 2 tan^2 a

Answer 1

$\textbf{Heya}$

Formula used :-

${(x - y)}^{2} = {x}^{2} + {y}^{2} - xy \\ \\ (x - y)(x + y) = {x}^{2} - {y}^{2} \\ \\ 1 + {tan \: }^{2} a = {sec}^{2} a$


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