Question

How to simply it
secx+1)(secx-1)/sin^2x

Answer 1

`\textit{Pythagorean Identities} \\\\ 1+\tan^2(\theta)=\sec^2(\theta)\implies \tan^2(\theta)=\sec^2(\theta)-1 \\\\[-0.35em] ~\dotfill\\\\ \cfrac{\stackrel{ \textit{difference of squares} }{[sec(x)+1][sec(x)-1]}}{sin^2(x)}\implies \cfrac{sec(x)^2-1^2}{sin^2(x)}\implies \cfrac{sec(x)^2-1}{sin^2(x)} \\\\\\ \cfrac{tan^2(x)}{sin^2(x)}\implies \cfrac{sin^2(x)}{cos^2(x)}\cdot \cfrac{1}{sin^2(x)}\implies \cfrac{1}{cos^2(x)}\implies sec^2(x)`