A) \[\frac{{{a}^{2}}+{{b}^{2}}+{{c}^{2}}}{abc}\]
B) \[\frac{{{a}^{2}}+{{b}^{2}}+{{c}^{2}}}{2abc}\]
C) \[\frac{2({{a}^{2}}+{{b}^{2}}+{{c}^{2}})}{abc}\]
D) \[{{a}^{2}}+{{b}^{2}}+{{c}^{2}}\]
Correct Answer: B
Solution :
\[\frac{\cos A}{a}+\frac{\cos B}{b}+\frac{\cos C}{c}\] \[=\frac{{{b}^{2}}+{{c}^{2}}-{{a}^{2}}+{{a}^{2}}+{{c}^{2}}-{{b}^{2}}+{{a}^{2}}+{{b}^{2}}-{{c}^{2}}}{2abc}\] = \[\frac{{{a}^{2}}+{{b}^{2}}+{{c}^{2}}}{2abc}\].You need to login to perform this action.
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