यदि cos A = cos B,,cos C और A + B + C = | vedclass

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Question

(d) यहाँ $\cos A = \cos B\cos C$

$A + B + C = \pi  \Rightarrow B + C = \pi  - A$

 $	herefore \cos (B + C) = \cos (\pi  - A)

Vedclass · Accepted Answer

$\frac{1}{2}$

Vedclass · Answer

(d) यहाँ $\cos A = \cos B\cos C$

$A + B + C = \pi  \Rightarrow B + C = \pi  - A$

 $	herefore \cos (B + C) = \cos (\pi  - A) \Rightarrow \cos (B + C) =  - \cos A$

$ \Rightarrow \cos B\cos C - \sin B\sin C =  - \cos B\cos C$

$( \because {m{Given}}\cos A = \cos B\cos C)$ 

 $ \Rightarrow 2\cos B\cos C = \sin B\sin C$

$ \Rightarrow \frac{{\cos B\cos C}}{{\sin B\sin C}} = \frac{1}{2}$

$\Rightarrow \cot B\cot C = \frac{1}{2}$.

यदि $\cos A = \cos B\,\,\cos C$ और $A + B + C = \pi ,$ तो $\cot \,B\,\cot \,C$ का मान है

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