Question

Determine the equations of the following circle with its center at the origin and (2;-1) a point of a circle

Answer 1

Answer:

(x)^2 + (y)^2 = 5

Step-by-step explanation:

Since the center of the circle is (0, 0). We use the distance formula to find the radius, since (2, -1) is part of the circumference.

Distance formula = $\sqrt{(2-0)^{2}+(-1-0)^{2} }$

Solving this we get the radius $\sqrt{5}$

Plugging all this into the standard circle equation we get $(x-0)^{2} + (y-0)^{2} = \sqrt{5} ^{2}$

Thus getting (x)^2 + (y)^2 = 5