Find the number of solutions of $\sec x + \tan x = 2\cos x$ in $[0, 2\pi]$.
(A) 0 (B) 1 (C) 2 (D) 3
(C) $x = \pi/6, 5\pi/6$
Find the number of solutions of $\sec x + \tan x = 2\cos x$ in $[0, 2\pi]$.

(A) 0 \quad (B) 1 \quad (C) 2 \quad (D) 3