Question

如图,在矩形ABCD中,AB=3,BC=4,P是边AD上一点,过三点A,B,P作圆O 求当CD与圆O相切时,BC被圆O截

Answer 1

设AP=X时,圆O与CD切于F

OP=OF=4-AP/2=4-0.5*X;

OP=BP/2=0.5√(X²+3²);

4-0.5*X=0.5√(X²+3²);

X=55/16

BC被圆O截得的弦长=AP=X=55/16