tolong jawab ya, dengan caranya

[tex] \frac{1}{1 - \frac{1}{1 + \frac{1}{ \tan ^{2} (x) } } } = \frac{1}{1 - \frac{1}{ \frac{ \tan ^{2} (x) + 1}{ \tan ^{2} (x) } } } = \frac{1}{1 - \frac{\tan ^{2} (x)}{ \tan ^{2} (x) + 1} } = \frac{1}{ \frac{ \tan ^{2} (x ) + 1 - \tan ^{2} (x)}{ \tan ^{2} (x) + 1} } = \frac{1}{ \frac{ 1}{ \tan ^{2} (x) + 1} } \\ = \tan ^{2} (x) + 1 = \frac{ \sin ^{2} (x) }{ \cos ^{2} (x) } + \frac{ \cos ^{2} (x) }{ \cos ^{2} (x) } = \frac{ \sin ^{2} (x) + \cos ^{2} (x) }{ \cos^{2} (x) } = \frac{1}{ \cos ^{2} (x) } \\ = \sec ^{2} (x) [/tex]