railway DMRC CRA Mock Test Series Quantitative Aptitude Trigonometry Trigonometric Ratios and Identities
Simplify the following expression by using identities.
\({\cos ^2}{\rm{x\;}}\left( {{{\sec }^2}{\rm{x}} - 1} \right)\)
1
\({\sin ^2}{\rm{x}}\)
2
\({\cos ^2}{\rm{x}}\)
3
\(\cos {\rm{x}}\)
4
\({\tan ^2}{\rm{x}}\)