if a is not in second quadrant b is not in third quadrant and cosa =-1/2 ,cosb =-1/2 then find the value of 4 sinb-3tana/tanb+sina
if a is not in second quadrant b is not in third quadrant and cosa =-1/2 ,cosb =-1/2 then find the value of 4 sinb-3tana/tanb+sina