Question
Question: In ∆ABC, if 2(bccos A + cacos B + abcos C) =...
In ∆ABC, if 2(bccos A + cacos B + abcos C) =
A
0
B
a + b + c
C
a2 + b2 + c2
D
None of these
Answer
a2 + b2 + c2
Explanation
Solution
2(bc cos A + ca cos B + ab cos C)
= 2
= a2 + b2 + c2