Q. One of the diameter of the circle $x^{2} + y^{2} - 2x + 4y - 4 = 0$ is
A) $x - y - 3 = 0$
B) $x + y - 3 = 0$
C) $- x + y - 3 = 0$
D) $x + y + 3 = 0$
Explanation
(a)
Equation of circle is $x^{2} + y^{2} - 2x + 4y - 4 = 0$
$\therefore$ Centre is $(1,\ - 2)$
As we know the equation of diameter is passing through centre
Now, taking option (a)
$ie,\ x - y - 3 = 0$
$\Rightarrow 1 + 2 - 3 = 0\ \Rightarrow 0 = 0$
$\therefore$ It is a required equation of diameter
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.