Thread: Circle Geometry

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.

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.

Well the centre of is and the radius is 4.

I found that the origin lies inside the circle since the distance to the origin from the centre is only which is smaller than 4.

They are the only preceding pieces of information I have.

The slope of the line determined by is .
Therefore the slope of the chord is . WHY?

Originally Posted by Plato

The slope of the line determined by is .
Therefore the slope of the chord is . WHY?

Since the chord is perpendicular to the tangent gradient you've found?

But how is AC a tangent gradient?

Originally Posted by Femto

Since the chord is perpendicular to the tangent gradient you've found?
But how is AC a tangent gradient?

The line determined by the center of a circle and the midpoint of a chord is the perpendicular bisector of the chord.

Oh right thanks very much I forgot about that!