Solve: (2cos x – 1 = 0).
-
A.
((frac{2pi}{3}, frac{4pi}{3})) -
B.
((frac{pi}{6}, frac{5pi}{6})) -
C.
((frac{pi}{5}, frac{2pi}{5})) -
D.
((frac{pi}{3}, frac{5pi}{3}))
Correct Answer: Option D
Explanation
(2cos x – 1 = 0 implies 2cos x = 1)
(cos x = frac{1}{2})
(x = cos^{-1} (frac{1}{2}))
= (frac{pi}{3}) = (frac{5pi}{3})