Hello, milan!
We complete the square and get: .
Make sketch . . . Code:
Figure 1
 o
 o
 * * * o
 * * P(14,3)
 * o
 * * *o
  +           *    o
 * * * o
 * C * *
 * (9,2) *

 * *
 * *
 * *
 * * *

The center of the circle is
Its radius is .
The equation of the tangent is: .
And its slope is 1.
A new diagram to examine one of the chords.
I rotated the diagram so the chord is horizontal. Code:
Figure 2
* * * _
Q * A 3√2 * P
*    +    *
* *  * _*
*  * 5√2
* *  * *
*     *     *
C
The radius is:
The chord is:
We see that is a 345 right triangle. .Hence: .
. . That is, the chord is from the center.
Look at Figure 1.
Point is of the way from to .
. . Hence, point is at .
The other chord cross the diameter at .
We know all about the two chords!
. . One contains and has slope .
. . The other has and has slope .
Go for it!