Step-by-step explanation:
[tex]\frac{(1-tan^{2}x)tan(2x) }{tanx} \\ but \: \tan(2x) = \frac{2 \tan(x) }{1 - { \tan }^{2}x } \\ therefore : \\ = \frac{(1 - { \tan ^{2}x)(2 \tan(x)) }}{ (\tan(x) )(1 - { \tan ^{2}x })} \\ = \frac{2 \tan(x) }{ \tan(x) } \\ = 2[/tex]
