The document provides steps to find the center and radius of a circle in the first quadrant containing the points (3,0) and (0,3). It reminds the reader of the standard circle equation and identifies that the center is (3,3) based on the points given. The radius is determined to be 3 based on the distance between the center and either point, resulting in the circle equation (x-3)2 + (y-3)2 = 9.

1. Circles

2. A Circle Problem Find the center and radius of the circle that lies in the first quadrant and contains the points (3, 0) and (0, 3).

3. Remember the Formula? Try writing down the formula for the standard equation of a circle, then click this slide to check to see if you are correct. (x – h) 2 + (y – k) 2 = r 2 Did you get it right? Click to continue…

4. What do we need to know? We have to find know both the coordinates of the center and the radius before we can write the equation.

5. What we know… If the circle lies in the first quadrant, we know the center must be at (3, 3) – see diagram. The radius is 3 (we can tell by counting). 3 3

6. Let’s write the equation… (x – 3) 2 + (y – 3) 2 = 3 2 (x – 3) 2 + (y – 3) 2 = 9