`2 tan A tan B = 1 =>(Cos(A-B))/(cos(A+B))`

if 3tan A tan B=1 then 2cos(A+B)

If 3tan A tan B=1, prove that 2cos(A+B)=cos(A-B)

If 3tan A tan B=1, prove that 2cos(A+B)=cos(A-B)dot

Prove that tan^2A - tan^2B = (sin(A+B).sin(A-B))/(cos^2A.cos^2B

tan A ++ tan B + tan C- (sin (A + B + C)) / (cos A cos B cos C) =

Prove the following tan^2A- tan^ 2B=(sin^2A-sin^2B)/(cos^2A*cos^2B) =(cos^2B-cos^2A) /(cos^2A*cos^2B)

If (x)/(y)=(cos A)/(cos B)then(x tan A+y tan B)/(x+y)=cot(A+B)/(2)(b)cot(A-B)/(2)tan(A-B)/(2) (d) tan(A+B)/(2)

If 2 tan A = 3 tan B.show that tan (A - B)= (sin2B)/(5-cos2B)

underset are in cos2B=(cos(A+C))/(cos(A-C))rArr tan A,tan B,tan C