In any `DeltaABC`, prove that : `(1+cos (A-B) cos C)/(1+cos (A-C) cos B) = (a^2 + b^2)/(a^2 + c^2)`

In any Delta ABC, prove that :(1+cos(A-B)cos C)/(1+cos(A-C)cos B)=(a^(2)+b^(2))/(a^(2)+c^(2))

In any triangle ABC, prove that: (1+cos(A-B)cos C)/(1+cos(A-C)cos B)=(a^(2)+b^(2))/(a^(2)+c^(2))

In any Delta ABC, prove that :a(b cos C-c cos B)=b^(2)-c^(2)

In any DelataABC prove that "a(cos C - cos B)=2(b-c)cos"^(2)A/2

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

In any Delta ABC, prove that :(b+c)cos((B+C)/(2))=a cos((B-C)/(2))])

In DeltaABC , prove that: (b+c)cos(B+C)/(2)=acos(B-C)/(2)

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)

In DeltaABC , prove that: a(cosC-cosB)=2(b-c)cos^(2)A/2