Trigonometric Equations Question 269
Question: In a $ \Delta ABC, $ $ 2a\sin ( \frac{A-B+C}{2} ) $ is equal to
[IIT Screening 2000]
Options:
A) $ a^{2}+b^{2}-c^{2} $
B) $ c^{2}+a^{2}-b^{2} $
C) $ b^{2}-c^{2}-a^{2} $
D) $ c^{2}-a^{2}-b^{2} $
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Answer:
Correct Answer: B
Solution:
- $ 2ac\sin \frac{A-B+C}{2}=2ac\sin \frac{\pi -2B}{2}=2ac\cos B $ = $ 2ac,\frac{c^{2}+a^{2}-b^{2}}{2ca}=c^{2}+a^{2}-b^{2} $ .
BETA
