Circle 1 Question 22
22. For how many values of $p$, the circle $x^{2}+y^{2}+2 x+4 y-p=0$ and the coordinate axes have exactly three common points?
(2017 Adv.)
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Solution:
- The circle and coordinate axes can have 3 common points, if it passes through origin. $[p=0]$
If circle is cutting one axis and touching other axis.
Only possibility is of touching $X$-axis and cutting
$Y$-axis. $[p=-1]$
