Trigonometric Equations Question 294
Question: In $ \Delta ABC $ , if $ 2s=a+b+c $ , then the value of $ \frac{s(s-a)}{bc}-\frac{(s-b)(s-c)}{bc}= $
Options:
A) $ \sin A $
B) $ \cos A $
C) $ \tan A $
D) None of these
Show Answer
Answer:
Correct Answer: B
Solution:
- $ {{\cos }^{2}}\frac{A}{2}-{{\sin }^{2}}\frac{A}{2}=\cos \frac{2A}{2}=\cos A. $
BETA
