In a Delta ABC,the expression frac{cos C + co | vedclass

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(B) Given expression: $\frac{\cos C + \cos A}{c + a} + \frac{\cos B}{b}$ Taking the common denominator $b(c + a)$,we get: $= \frac{b(\cos C + \cos A)

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$\frac{1}{b}$

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(B) Given expression: $\frac{\cos C + \cos A}{c + a} + \frac{\cos B}{b}$ Taking the common denominator $b(c + a)$,we get: $= \frac{b(\cos C + \cos A) + \cos B(c + a)}{b(c + a)}$ $= \frac{b \cos C + b \cos A + c \cos B + a \cos B}{b(c + a)}$ Using the projection formula,we know that $b \cos C + c \cos B = a$ and $b \cos A + a \cos B = c$. Substituting these values: $= \frac{(b \cos C + c \cos B) + (b \cos A + a \cos B)}{b(c + a)}$ $= \frac{a + c}{b(c + a)}$ $= \frac{1}{b}$.

In a $\Delta ABC$,the expression $\frac{\cos C + \cos A}{c + a} + \frac{\cos B}{b}$ is equal to:

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