∵ hyperbola y 1= 1/x (x > 0), y2 = 4/x (x > 0), and the axis of PA⊥x is at point A, the axis of PB⊥y is at point B, and PA and PB are respectively with hyperbola y1.

The area of rectangular BCEO is xy= 1,

∫BC×BO = 1，BP×BO=4，

∴BC=BP/4，

∫ao×AD = 1，AO×AP=4，

∴AD=AP/4，

∵PA？ PB=4，

∴3PB/4×3PA/4=9PA？ PB/ 16 = CP×DP = 9/ 16×4 = 9/4，

∴△△△ The area of PCD is nine eighths of it.

So the answer is: 9/8.