Question

If $tan(A-B)=\frac {1}{\sqrt 3},\ cos \ A=\frac 12$ then $∠B=$ ____ .

• A. $\frac {2\pi}{3}$
• B. $\frac {\pi}{4}$
• C. $\frac {\pi}{6}$
• D. $\frac {\pi}{3}$

Answer 1

Answer: (C)

$\frac {\pi}{6}$

Answer 2

The correct option is (C): $\frac {\pi}{6}$.