Question

If \( (b - c)\cos \frac{A}{2} = k \sin \frac{B - C}{2} \), then \( \frac{k}{\sin A} = \) :

• A. \( b \)
• B. \( 2R \)
• C. \( \sqrt{2R} \)
• D. \( a + c \)

Hint:

Replace sides using \(a=2R\sin A\) for quick simplification in triangle identities.

Answer 1

The Correct Option is B