Q. The centre and the radius of the circle $z\overline{z} + (2 + 3i)\overline{z} + (2 - 3i)z + 12 = 0$ are respectively
A) $- (2 + 3i),\ (1)$
B) $(3 + 2i),\ (1)$
C) $(3 + 6i),\ (3)$
D) None of these
Explanation
(a)
Given equation of circle is
$z\overline{z} + (2 + 3i)\overline{z} + (2 - 3i)z + 12 = 0$
Here, centre is {-(2+3$i$)} and radius
$= \sqrt{|2 + 3i|^{2} - 12} = \sqrt{13 - 12} = 1$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.