我证明过程就省略了
(2)连接OA,OD,OD交AB于E
AD²/BC
=(AE²+DE²)/BC
=(OA²-OE²+DE²)/2DE
=[R²-(R-DE)²+DE²]/2DE
=[R²-(R²-2R*DE+DE²)+DE²]/2DE
=(2R*DE)/2DE
=R
我证明过程就省略了
(2)连接OA,OD,OD交AB于E
AD²/BC
=(AE²+DE²)/BC
=(OA²-OE²+DE²)/2DE
=[R²-(R-DE)²+DE²]/2DE
=[R²-(R²-2R*DE+DE²)+DE²]/2DE
=(2R*DE)/2DE
=R