The centres of those circles which touch the circle, x2+y2−8x−8y−4=0, externally and also touch the x-axis, lie on :
an ellipse which is not a circle.
As we learnt in
Common tangents of two circles -
When two circles touch each other externally, there are three common tangents, two of them are direct.
Circle touching x-axis and having radius r -
Where f is a variable parameter.
Standard equation of parabola -
radius of circle touching x-axis=k,
On squaring both sides
Represent a parabola
Create Your Account