Teaching Jharkhand (JSSC) TGT (6 to 8) Mock Test 2023-24 Mathematics Trigonometry Trigonometric Identities
What is the value of \(\cos\left(\frac{\pi}{9}\right)+\cos\left(\frac{\pi}{3}\right)+\cos\left(\frac{5\pi}{9}\right)+\cos\left(\frac{7\pi}{9}\right)\)?
1
1
2
-1
3
\(-\frac{1}{2}\)
4
\(\frac{1}{2}\)