Question

prove that following identities
4 tan square A - 4/ cos square A= -4​

Answer 1

$4 { \tan}^{2} x - \frac{4}{ { \cos}^{2} x} \\ \\ \\ = \frac{4 { \sin}^{2} x}{ { \cos}^{2} x} - \frac{4}{ { \cos}^{2} x} \\ \\ \\ = 4( \frac{ { \sin}^{2}x - 1 }{ { \cos}^{2} x} ) \\ \\ \\ = - 4( \frac{1 - { \sin }^{2} x}{ { \cos }^{2}x } ) \\ \\ \\ = - 4$

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