`(b-c)/a cos^2(A/2)+(c-a)/bcos^2(B/2)+(a-b)/c cos^2(C/2)=`

In DeltaABC , prove that: (b-c)/acos^(2)A/2+(c-a)/(b)cos^(2)B/2+(a-b)/(c ).cos^(2)C/2=0

In a DeltaA B C , prove the following : 4\ (b c cos^2(A/2)+c acos^2(B/2)+a bcos^2(C/2)\ )\ =(a+b+c)^2

If A+B+C=pi then prove cos( (A)/2) cos( (B-C)/2) + cos( B/2) cos((C-A)/2) + cos( C/2) cos( (A-B)/2) = sinA +sinB+sinC

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

(iv) a^(2)(cos^(2) B - cos^(2)C) + b^(2) (cos^(2) C- cos^(2)A) + c^(2) (cos^(2)A- cos^(2)B)=0

(b^(2)-c^(2))/(a)cos A+(c^(2)-a^(2))/(b)cos B+(a^(2)-b^(2))/(c)cos C=0

If A,B and C are positive such that A+B+C=pi; find then the minimum value of (cos(A-B)/2)/(cos(A+B)/2)+(cos(B-C)/2)/(cos(B+C)/2)+(cos(C-A)/2)/(cos(C+A)/2)

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