If \(sin \ \theta + cos \ \theta = p\) and \(sec \ \theta + cosec \ \theta = q\), then prove that \(q(p^2 - 1) = 2p\).
 
Proof:
 
\(p \)
---- (\(1\))
 
\(q\)
---- (\(2\))
 
 LHS \(= q(p^2 - 1)\)
 
From equations (1) and (2)
 
\(LHS=\)
 
\(= 2p\) 
 
\(=\) RHS
 
 Hence, we proved.
Answer variants:
\(= \frac{p}{sin \ \theta \ cos \ \theta}\)
\(= \frac{p}{sin \ \theta \ cos \ \theta}(2 sin \ \theta \ cos \ \theta)\)
\(= 1 + 2 sin \ \theta \ cos \ \theta\)