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The standard form of a circle is as follows:
- (x - h)² + (y - k)² = r², where (h, k) is the center of the circle and r is its radius.
We are given that (h, k) = (0, - 3) and we need to find the value of r².
We know that radius is the distance from the center to a point on the circle.
Recall the distance formula:
Here, (x₁, y₁) and (x₂, y₂) refer to the coordinates of two points in space.
Substitute the given coordinates and find the radius:
Now, we can write the equation of a circle in standard form:
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