Step-by-step explanation:
[tex] \frac{ \tan {}^{2} (x) + 1 }{ \tan {}^{2} (x) } = \csc {}^{2} (x) [/tex]
[tex] \frac{ \tan {}^{2} (x) }{ \tan {}^{2} (x) } + \frac{1}{ \tan {}^{2} (x) } = \csc {}^{2} (x) [/tex]
[tex]1 + \frac{1}{ \tan {}^{2} (x) } = \csc {}^{2} (x) [/tex]
[tex]1 + \cot {}^{2} (x) = \csc {}^{2} (x) [/tex]
[tex] \csc {}^{2} (x) = \csc {}^{2} (x) [/tex]