If `A+B=pi/3` and `cosA+cosB=1` then

If A + B =(pi)/(3) and cosA + cosB = 1then the value of cos ((A-B)/2) is_______

If A+B+C=pi, and cosA=cosB*cosC then tanB*tanC has the value equal to (i)1 (ii)1/2 (iii)2 (iv)3

If sinA+sinB=a and cosA+cosB=b,then cos(A+B)

If sinA+sinB=a and cosA+cosB=b,then cos(A+B)

If A+B+C=pi and cosA=cosB.cosC show that tanB+tanC=tanA

If A+B+C=pi and cosA=cosB.cosC show that 2cotB.cotC=1

If cosA=4/5 and cosB=12/13 , then find the values of cos(A+B) and sin(A-B) , where A , B ((3pi)/(2) to 2pi ) .

If sinA+sinB=l and cosA-cosA-cosB=m , then cos(A-B)=

If A+B+C= pi and cosA+cosB+cosC=0=sinA+sinB+sinC then cos3A+cos3B+cos3C=