Review question

# Can we show these two circles lie entirely outside each other? Add to your resource collection Remove from your resource collection Add notes to this resource View your notes for this resource

Ref: R6390

## Question

Prove that the points whose coordinates satisfy the equation $x^2+y^2+2gx+2fy+c=0$ lie on a circle. State the coordinates of the centre of the circle and the length of its radius.

Prove that the circles $x^2+y^2-20x-16y+128=0$ and $4x^2+4y^2+16x-24y-29=0$ lie entirely outside each other, and find the length of the shortest distance from a point on one circle to a point on the other.