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

(cos A-cos B+cos C+1)/(cos A+cos B+cos C-1) =

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))

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)

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

If A+ B + C = pi, then cos^(2) A + cos ^(2) B + cos ^(2) C is equal to : A) 1 - cos A cos B cos C B) 1 - 2 cos A cos B cos C C) 2 cos A cos B cos C D) 1 + cos A cos B cos C

If A+B+C=180^(@) then cos2A+cos2B+cos2C=1-4cos A cos B cos C 2.If A+B+C=0 then cos A+cos B+cos C=-1+4(cos A)/(2)(cos B)/(2)(cos C)/(2)

If A + B + C = 180^(@) , prove that cos A + cos B - cos C = -1 + 4 cos (A)/(2) cos"" (B)/(2) sin"" (C )/(2)

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