How to Easily Find the Radius from a Circle Equation
Learn to find the radius of a circle from its equation in standard form with simple steps and examples.
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To find the radius from a circle equation in standard form (x - h)^2 + (y - k)^2 = r^2, identify the term r^2. Simply take the square root of this value to get the radius. For example, if the equation is (x - 3)^2 + (y + 2)^2 = 16, the radius is √16, which equals 4. The center of the circle is at point (h, k) or (3, -2) in this example.
FAQs & Answers
- What is the standard form of a circle equation? The standard form of a circle equation is (x - h)^2 + (y - k)^2 = r^2, where (h, k) is the center and r is the radius.
- How do you determine the center of a circle from its equation? The center of a circle can be found from its equation in standard form (x - h)^2 + (y - k)^2 = r^2 as the point (h, k).
- Can you find the radius if the equation is not in standard form? Yes, you can convert the circle equation into standard form to find the radius using the formula (x - h)^2 + (y - k)^2 = r^2.