[(b+c)cos A+(c+a)cos B+(a+b)cos C],[a^(2)cos2B+b^(2)cos2A+2ab cos(A-B)=c^(2)]

a ^ (2) cos2B + b ^ (2) cos2A + 2ab cos (AB) = c ^ (2)

a ^ (2) cos2B + b ^ (2) cos2A + 2ab cos (AB) = c ^ (2)

a ^ (2) cos (2B) + b ^ (2) cos (@A) + 2ab cos (AB) = c ^ (2)

2(bc cos A+ca cos B+ab cos C)=a^(2)+b^(2)+c^(2)

(cos A)/(a)+(cos B)/(b)+(cos C)/(c)=(a^(2)+b^(2)+c^(2))/(2abc)

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 : (cos A)/(b cos C+c cos B)+(cos B)/(c cos A+a cos C)+(cos C)/(c cos B+b cos A)=(a^(2)+b^(2)+c^(2))/(2abc)

In any Delta ABC, prove that: (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))/(2abc)

Prove in any triangle ABC that (i) a^(2)+b^(2)+c^(2)=2(bc cos A +ca cos B+ ab cos C) (ii) (b+c) cos A+(c+a)cos B+(a+b) cos C = a+b+c .