Buktikan identitas trigonometri berikut 2-sec²A/sec²A = 1-2sin²A pake cara+penjelasan(kalo bisa:) ) terimakasih

[tex] \frac{2 - { \sec( \alpha ) }^{2} }{ { \sec( \alpha ) }^{2} } = 1 - 2 { \sin( \alpha ) }^{2} \\ \frac{2 - { \sec( \alpha ) }^{2} }{ { \sec( \alpha ) }^{2} } = 1 - 2(1 - { \cos( \alpha ) }^{2} ) \\ \frac{2 - { \sec( \alpha ) }^{2} }{ { \sec( \alpha ) }^{2} } = 2 { \cos( \alpha ) }^{2} - 1 \\ \frac{2 - { \sec( \alpha ) }^{2} }{ { \sec( \alpha ) }^{2} } = 2( \frac{1}{ { \sec( \alpha ) }^{2} } ) - 1 \\ \frac{2 - { \sec( \alpha ) }^{2} }{ { \sec( \alpha ) }^{2} } = \frac{2}{ { \sec( \alpha ) }^{2} } - 1 \\ \frac{2 - { \sec( \alpha ) }^{2} }{ { \sec( \alpha ) }^{2} } = \frac{2 - { \sec( \alpha ) }^{2} }{ { \sec( \alpha ) }^{2} } \: \: (terbukti)[/tex]