If $$\sin \theta = \frac{{{p^2} - 1}}{{{p^2} + 1}},$$   then cosθ is equal to:

A. $$\frac{{2p}}{{1 + {p^2}}}$$

B. $$\frac{p}{{{p^2} - 1}}$$

C. $$\frac{p}{{1 + {p^2}}}$$

D. $$\frac{{2p}}{{{p^2} - 1}}$$

Answer: Option A

Solution(By Examveda Team)

$$\eqalign{ & \sin \theta = \frac{{{p^2} - 1}}{{{p^2} + 1}} \cr & {\text{Let }}p = 2 \cr} $$

$$\eqalign{ & {\text{Now from option A}} \cr & \frac{{2 \times 2}}{{1 + 4}} = \frac{4}{5} \cr} $$