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

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

If tanA.tanB=1/2,t h e n(5-3cos2A)(5-3cos2B)= (a)2 (b) 8 (c) 12 (d) 16

If tanA.tanB=1/2,t h e n(5-3cos2A)(5-3cos2B)= (a)2 (b) 8 (c) 12 (d) 16

If tanA.tanB=1/2,t h e n(5-3cos2A)(5-3cos2B)= (a)2 (b) 8 (c) 12 (d) 16

If 3tanA tanB=1 , then prove that 2cos(A+B)=cos(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

Let A , B , C be the three angles such that A+B+C=pi . If tanAtanB=2, then find the value of (cos(A-B))/(cosC)

Let A , B , C be the three angles such that A+B+C=pi . If tanA.tanB=2, then find the value of (cosAcosB)/(cosC)