Question

Express the trigonnmetric ratios cos A and sec A in terms of sin A

Answer 1

$\cos( \alpha ) = \sin(90 - \alpha ) \\ \cos \alpha = \frac{1}{ \sec( \alpha ) } \\ \sec( \alpha ) = { \sin(90 - \alpha ) }^{( - 1)} = \frac{1}{ \sin(90 - \alpha ) }$

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