`cotAcotB=2,cos(A+B)=3/5=>sinAsinB=`

If 2cos A+3cos B+5cos C=0=2sin A+3sin B+5sin C then 3A+27cos3B+125cos3C=k cos(A+B+C) then k is

If cos(A-B)=(3)/(5) andtan Atan B=2, then cos A cos B=(1)/(5)(b)sin A sin B=-(2)/(5)cos A cos B=-(1)/(5)(d)sin A sin B=-(1)/(5)

If cos(A-B)=3/5 and tan A tan B=2, then (a) cos A cos B=1/5 (b) sin A sin B=-2/5 (c) cos A cos B=-1/5 (d) sin A sin B=-1/5

If cos(A-B)=3/5 and tanAtanB=2 then

If cos(A-B)=3/5 and tanAtanB=2 then......................... A) cos A cos B=1/5 B) sin A sin B = -2/5 C) cos A cos B =-1/5 D) sin A sin B =-1/5

prove that cos(A+B)=cosAcosB-sinAsinB

If A=B=45^(@) , show that : cos(A+B)=cosAcosB-sinAsinB

If A=30^@ and B=60^@ ,show that (ii)cos(A+B)=cosAcosB-sinAsinB