Question

to find the standard equation for a circle centered at the origin, we use the distance formula, since the radius measures?
a. the distance from any point in the circle to the origin.
b. the circumference
c. the distance from any point inside the circle to the origin.
d. the distance from the x-coordinate to the origin.

Answer 1

The distance from any point on the circle to the origin

Answer 2

Answer: The answer is (a). the distance from any point in the circle to the origin.

Step-by-step explanation:  We know that to find the standard equation of a circle centred at the origin, we always use the distance formula. We are to select the correct measurement for the radius from the options given.

In a circle, as shown in the attached figure, the radius 'r' is the distance from any point 'P' on the circle to the centre 'O' of the circle. The centre of the circle in standard form is usually the origin.

So, we can say that radius measures the distance from any point on the circle to the origin.

Thus, (a) is the correct option.