Q. The equation of two circles which touch the $y$-axis at (0, 3) and make an intercept of 8 unit on $x$-axis, are
A) $x^{2} + y^{2} \pm 10x - 6y + 9 = 0$
B) $x^{2} + y^{2} \pm 6x - 10y + 9 = 0$
C) $x^{2} + y^{2} - 8x \pm 10y + 9 = 0$
D) $x^{2} + y^{2} \pm 10x \pm 6y + 9 = 0$
Explanation
(a)
Given, equation of circle touch the $y$-axis at (0, 3).
In $\mathrm{\Delta}OAB,\ \ r = \sqrt{3^{2} + 4^{2}} = 5$
The point (0, 3) and radius 5 satisfies the equation
$x^{2} + y^{2} \pm 10x - 6y + 9 = 0$
[image:11_image25.emf]
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.