In a `Delta`ABC, prove that
a ( cos B + cos C) = 2 (b + c) `sin^(2)""(A)/(2)`

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

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

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

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

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

In a triangle ABC, prove that (a) cos(A + B) + cos C = 0 (b) tan( (A+B)/2)= cot(C/ 2)

In any Delta ABC, prove that ”a cos”(B-C)/2=(b+c) “sin” A/2

In any triangle ABC, prove that a cos A+b cos B +c cos C =(8 triangle^(2))/(abc) .

In /_\ABC ,Prove that a cos A + b cos B + c cos C = 2a sin B sin C

Prove in any triangle ABC that (i) a(cos B+cos C)=2(b+c) "sin"^(2)(A)/(2) (ii) a(cos C- cosB)= 2(b-c )"cos"^(2)(A)/(2)