Understanding the Formula for the Center and Radius of a Circle

Learn how to find the center and radius of a circle from its equation with our simple guide.

208 views

To find the center and radius of a circle given its equation in the general form (x - h)^2 + (y - k)^2 = r^2, the center is (h, k) and the radius is r. For instance, in (x - 3)^2 + (y + 2)^2 = 16, the center is (3, -2) and the radius is 4.

FAQs & Answers

  1. How do you identify the center and radius of a circle from its equation? To identify the center and radius from the equation of a circle in the form (x - h)² + (y - k)² = r², the center is given by the coordinates (h, k), and the radius is the square root of r².
  2. What does the general form of a circle's equation look like? The general form of a circle's equation is (x - h)² + (y - k)² = r², where (h, k) represents the center, and r is the radius.
  3. Can you provide an example of finding the center and radius of a circle? Yes! For the equation (x - 3)² + (y + 2)² = 16, the center is (3, -2) and the radius is 4, since r is the square root of 16.
  4. Why is knowing the center and radius of a circle important? Knowing the center and radius is crucial in geometry for graphing circles, solving related mathematical problems, and understanding their properties.