Distance from center of circle to straight line d:

d = | k+ 1+ 1 |/√( 1+k？ )

=|k+2|/√( 1+k？ )& ltr

k？ +2k+ 1 & lt； 20( 1+k？ )

19k？ -2k+ 19 & gt； 0

△= 4-4x 19x 19 & lt； 0

No matter what value k takes, the inequality holds, that is, D.

So both a straight line and a circle have two intersections.

(2) Chord length =2√(r? -Dee? )

=2√[20-(k？ +2k+ 1)/( 1+k？ )]

=2√[ 19-2k/( 1+k？ )]

1+k? ≥2k k & gt； 0 means k= 1, and there is a minimum value.

The shortest chord length =2√ 18

=6√2