As written there are infinitely many answers.
Therefore, you have posted only a very small part of the complete question.
Please revise the question giving all the information.
The point A has coordinates . Find the equation of the chord of the circle which has as its midpoint.
I don't know how to do it with limited information. Could somebody help please? I'm a bit shoddy at these questions.
It has preceding questions which say let be the circle with equation
I found the centre and radius.
Then it asked me to determine whether the origin lies inside or outside C; it lies inside.