Discussion Forum

For how many values of p, the circle $x^{2}+y^{2}+2x+4y-p=0$ and the coordinate axes have exactly three common points?

Answer:

Explanation:

The circle and coordinate axis can have 3 common points. If it passes through the origin (p=0)

 If the circle is cutting one axis and touching another axis

 The only possibility is one of touching X-axis and cutting Y-axis [P=-1]