In any `DeltaABC`, prove that : `(cos A)/a + a/(bc) = (cos B)/b + b/(ca) = (cos c)/c + c/(ab)`

In any DeltaABC , prove that (sin B)/(sin C) = (c-a cos B)/(b-a cos C)

In any DeltaABC , 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 a DeltaA B C prove that cos(A+B)+cos C=0.

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

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

In any DeltaABC , prove that (cos2A)/a^(2)-(cos2B)/b^(2)=1/a^(2)-1/b^(2)

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

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

Prove that (cos C + cos A)/(c + a) + (cos B)/(b) = (1)/(b)

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