If any triangle ABC with usual notations prove `c=a cos B + b cos A`.

In a triangle ABC , with usual notations , prove that (a-bcosC)/(b-acosC)=(cosB)/(cosA) .

In triangle ABC , with the usual notations , prove that 2{a sin^(2).(C)/(2)+csin^2.(A)/(2)}=a+c-b

If in a triangle ABC, in the usual notation, 2a cos ((B-C)/(2))=b+c and Be neC . Then the measure of the angle A is

In Delta ABC with usual notation, (c-b cos A)/(a) is equal to

In Delta ABC , with usual notations prove that : b^(2) = c^(2) +a^(2) - 2 ca cos B .

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

In a Delta ABC with usual notations, if (a)/(cos A)=(b)/(cos B)=(c )/(cos C) , then the triangle is :

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

In any triangle ABC, then by vectors, prove that : a=b cos C+c cos B .

In DeltaABC with usual notation, (c-b cos A)/(a) is equal to