" 10."(1-cos A+cos B-cos(A+B))/(1+cos A-cos B-cos(A+B))=tan(A)/(2)cot(B)/(2)

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

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)

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))

(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))

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))

cos^(2) (A-B)+cos^(2)B-2cos(A-B) cos A cos B =

1-cos A + cos B-cos (A + B) * AB tan-cot-1 + cos A-cos B-cos (A + B) cod-cod CO-coc0-ces-A cos

(1+cos A*cos(B-C))/(1+cos C*cos(A-B))=(b^(2)+c^(2))/(a^(2)+b^(2))