Trigonometric Equations Question 49
Question: In $ \Delta ABC,\ a(b\cos C-c\cos B)= $
[EAMCET 1981]
Options:
A) $ a^{2}-b^{2} $
B) $ b^{2}-c^{2} $
C) $ c^{2}-a^{2} $
D) $ a^{2}+b^{2}+c^{2} $
Show Answer
Answer:
Correct Answer: B
Solution:
- $ a(b\cos C-c\cos B)=ab\cos C-ac\cos B $ = $ \frac{a^{2}+b^{2}-c^{2}}{2}-\frac{a^{2}+c^{2}-b^{2}}{2}=b^{2}-c^{2} $ .
BETA
