railway RRB NTPC Mock Test Series 2024-25 (CBT 1 + CBT 2) Quantitative Aptitude Trigonometry Trigonometric Ratios and Identities
If \({\cos ^2}a + cosa - 1 = 0\), then, find the value of \({\sec ^2}a - {\tan ^2}\left( {\frac{\pi }{2} - a} \right)\)?
1
1
2
-1
3
2
4
-2