In a `Delta ABC`, `a (cos^2 B+ cos^2 C)+cos A (c cos C+b cos B)` is equal to

In a Delta ABC, the value of (a cos A+b cos B+c cos C)/(a+b+c) is equal to

With usual notations, in triangle ABC, a cos (B - C) + b cos (C - A) + c cos (A - B) is equal to

In a triangle ABC, a cos A+b cos B+ c cos C=

In a Delta ABC,(cos A cos B)/(ab)+(cos B cos C)/(bc)+(cos C cos A)/(ca) is equal to

In any triangle ABC, the valur of a (cos ^(2) B+ cos ^(2)C)+ cos A (b cos B+ c cos C) is-

In Delta ABC, (cos C+ cos A)/(c+a)+(cos B)/b=

In a Delta ABC if (cos A)/(b cos C+c cos B)+(cos B)/(c cos A+a cos C)+(cos C)/(a cos B+b cos A)=(a^(2)+b^(2)+c^(2))/(Kabc) then K^(k) is equal to

In any Delta ABC, prove that :a cos A+b cos B+c cos C=2a sin B sin C