defence exam Agniveer Vayu Group X & XY Mock Test 01/2026 Mathematics Trigonometry Trigonometric Identities
\(\sqrt{2+\sqrt{2+\sqrt{2+2 \cos 8 \theta}}}\) where \(\theta \in\left[-\frac{\pi}{8}, \frac{\pi}{8}\right]\) is equal to
1
sin 2θ
2
2 cos θ
3
cos 2θ
4
2 sin θ