List of top Mathematics Questions on Trigonometric Identities asked in Bihar Board X

\( \sec^2 23^\circ - \tan^2 23^\circ + 2 \) is:
If \( x \cos \theta = 1 \), \( \tan \theta = y \), then the value of \( x^2 - y^2 \) is:
\( \frac{1 + \cos A}{1 - \cos A} \) is equal to: