If x,y and z are in AP, then x, y-1 and z are in?
Option (c) Take y=2 and = 1 and (y+z)/(1-yz) = 3
When y=2. x= -1/3 and z= 1/7,
= 1/2 = y-1 .. hence they are in HP
if the lines ax+2y+1=0, bx+3y+1=0, cx+4y+1=0 are concurrent then a,b,c are in:
a) AP
b)GP
c)HP
d)Neither GP or AP