$解:設(shè)?P?點的坐標(biāo)為?(4t，??\frac {1}{t})?$
$所以?D?點的橫坐標(biāo)為?4t，??C?點的縱坐標(biāo)為?\frac {1}{t}?$
$因為點?C，??D?在反比例函數(shù)?y=\frac {1}{x}?上$
$所以?D(4t，??\frac {1}{4t})，??C(t，??\frac {1}{t})?$
$所以?PC=3t，??PD=\frac {1}{t}-\frac {1}{4t}=\frac {3}{4t}?$
$?S_{△PCD}=\frac {1}{2}×PC×PD=\frac {1}{2}×3t×\frac {3}{4t}=\frac {9}{8}?$
