In △ ABC, if 2(bc cos A + ca cos B + ab cos C) =
0
a+b+c
a2+b2+c2
None of these
On putting the values of cos A, cos B and cos C, we get the required result i.e., a2+b2+c2.
2(bc cos A+ca cos B+ab cos C)=a2+b2+c2
2(bc cos A+ ca cos B + ab cos C)=