" 放."(cos2B+cos2A)/(cos2B-cos2A)=cot(A+B)cot(A-B)

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

(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))

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

Prove the following : cos2A+cos2B+cos2(A-B)+1 = 4cosA.cosB.cos(A-B)

If none of A,B, A+B is an integral multiple of pi , then prove that (1- cos A+ cos B- cos (A+B))/(1+ cos A- cos B - cos (A+B))=tan.(A)/(2) cot. (B)/(2)

Prove: cot^(2)A cos ec^(2)B-cot^(2)B cos ec^(2)A=cot^(2)A-cot^(2)B

Prove that (1-cos A+cos B-cos(A+B))/(1+cos A-cos B-cos(A+B))=tan((A)/(2))cot((B)/(2))

(1-cos A+cos B-cos(A+B))/(1+cos A-cos B-cos(A+B))=(tan A)/(2)(cot B)/(2)

In Delta ABC, show that (1-cos A+cos B+cos C)/(1-cos C+cos A+cos B)=tan((A)/(2))cot((C)/(2))