1. Precalculus Functions & Graphs Notes Standard Form for Equation of a Circle 2.2B Graphs of Equations Where (h, k) is the center and r is the radius. Equations for Semi-Circles Upper Half Lower Half Right Half Left Half

2. Precalculus Functions & Graphs Example #1 Sketch the graph of the circle or semi-circle. 2.2B Graphs of Equations First find the center and radius. Center (2, -3) and radius = 5. Plot the center then from the center go up five down five left five and right five. Then draw the circle around the points.

3. Precalculus Functions & Graphs You Try #1 Sketch the graph of the circle or semi-circle. 2.2B Graphs of Equations First find the center and radius. Center (0, 0) and radius = 7. Lower half Plot the center then from the center go down seven left seven and right seven. Then draw the circle around the points. Not a Quizdom problem.

4. Precalculus Functions & Graphs Example #2 Find an equation of the circle that satisfies the stated conditions. 2.2B Graphs of Equations Center (-4, 8) and radius = 12.

5. Precalculus Functions & Graphs You Try #2 Find an equation of the circle that satisfies the stated conditions. 2.2B Graphs of Equations Center (3, 0) and radius = 13. Answer choices will appear after you have had time to try the problem. Answer is A

6. Precalculus Functions & Graphs Example #3 Find an equation of the circle that satisfies the stated conditions. 2.2B Graphs of Equations Center (1, -2) and passing through (0, 3). Use the distance formula to find the radius.

7. Precalculus Functions & Graphs You Try #3 Find an equation of the circle that satisfies the stated conditions. 2.2B Graphs of Equations Center (2, 4) and passing through (-1, -1). Answer choices will appear after you have had time to try the problem.

8. Precalculus Functions & Graphs Example #4 Find the center and radius of the circle with the given equation. 2.2B Graphs of Equations You must complete the square twice. Regroup the x’s and the y’s and move the constant. Factor out the 4’s and leave a space.

9. Precalculus Functions & Graphs Example #4 Continued Find the center and radius of the circle with the given equation. 2.2B Graphs of Equations You must complete the square twice. Fill out the spaces by taking the middle term and dividing by two and squaring. Make sure to add the same amount to the other side Factor Divide by 4

10. Precalculus Functions & Graphs You Try #4 Find the center and radius of the circle with the given equation. 2.2B Graphs of Equations Answer choices will appear after you have had time to try the problem.