" Question: "underset(1)(a,b,c)/(cos A)cot(A)/(2),quad cos B cot(B)/(2),,cos**cot(C)/(2)are in A*P.

If a,b and c be in A.P. prove that cos A cot((A)/(2)),cos B cot((B)/(2)), and cos C cot((C)/(2)) are in A.P.

If a,b,c are in A.P then cot((A)/(2)),cot((B)/(2)),cot((C)/(2)) are in

(cos A+cos B)/(cos B-cos A)=cot((A+B)/(2))cot((A-B)/(2))

If a, b, c are in A.P then cot(A/2),cot(B/2),cot(C/2) are in

Prove that: (cos A+cos B)/(cos B-cos A)=cot((A+B)/(2))cot((A-B)/(2))

Prove that: (cos A+cos B)/(cos B-cos A)=cot((A+B)/2)cot((A-B)/2)

cot((A)/(2))+cot((B)/(2))+cot((C)/(2))=cot((A)/(2))cot((B)/(2))cot((C)/(2))

(sin A-sin B)/(cos B-cos A)=cot((A+B)/(2))

If acos^2(C/2)+c cos^2(A/2)=(3b)/2 . To prove: cot(A/2),cot(B/2),cot(C/2) are in A.P.

In any !ABC ,If cot(A/2),cot(B/2),cot(C/2) are in A.P.,then a,b,c are in