Solution: (1) Prove: If the passing point C is CG⊥x axis and the vertical foot is G, then CG=y 1, OG = X 1.

∵ point C(x 1, y 1) is in hyperbola y=,

∴x 1=

∵ In Rt△OCG, CG < oc < CG+og,

∴y 1