# Geo4.27

From Example Problems

Find the equation to the circle passing through the points (1,-2),(4,-3) and having the centre on the line

Let the equation of the circle be

The circle passes through (1.-2)

Hence

Let this equation be 1.

The circle passes through (4.-3)

Hence

Let this equation be 2.

Now the centre (-g,-f)lies on 3x+4y=7.

Hence

Let this equation be 3.

Solving 1 and 3 we get

Let this be 4.

Now solving 2 and 3 we get

Let this be 5.

Solving 4 and 5 we get

Now

The value of f is

Hence the equation of the circle is