Question

A circle has center at –6 + 2i and a point on the circle at 4 + 26i. Which of the following points is also on the circle?

–19 + 15i
–16 – 22i
6 + 16i
20 – 24i

Answer 1

Answer:
–16 – 22i
Explanation:
The radius of the circle = 4 + 26i - (-6 + 2i)
= 10 + 24i.
The radius will be the absolute values of this |10 + 24i|.

If a point is on the circle then it's distance from the centre must be 10+ 24i.
-19 + 15i - (-6 + 2i) = -13 - 13i , so this is not on the circle.
-16 - 22i - (-6 + 2i) = -10 - 24i = |10 + 24i| , so this is on the circle.
5 + 16i - (-6 + 2i) = 11 + 14i , so this is not on the circle.
20 - 24i - (-6 + 2i) = 26 - 26i. so this is not on the circle.