If p denote the arithmetic mean, q denote G.M. of the intercepts made on axes by the lines passing through (1, 1) then (p, q) lies on

p=a+b2,q=ab                 (1,1)   Lies on xa+yb=1                 ⇒1a+1b=1⇒a+b=ab                                                 ⇒2p=q2                 Required  locus is y2=2x