(2004•日照)如图,AB是⊙O的直径,点P在BA的延长线上,弦CD⊥AB于点E,∠POC=∠PCE.
(1)求证:PC是⊙O的切线;
(2)若OE:EA=1:2,PA=6,求⊙O的半径;
(3)求sin∠PCA的值.
考点分析:
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