Section 1.5

Circles

OBJECTIVES-Write standard form for the equation of a circle.-Find the intercepts of a circle and graph.-Write the general form for the equation of a circle.-Use completing the square to change find center and radius of a circle.

Write the standard form of the equation of the circle with radius 4 and center (2, -4).

Find the general equation of the circle whose center is (-2, 3) and whose graph contains the point (1, 4).

end of day1

11

• Graph the equation.

x2 y2 10x 4y 20 0

12

• Find the center and radius. Graph and find the intercepts. # 21)2(x 3)2 2y2 8

13

• Find the center and radius. Graph and find the intercepts. # 29)2x2 2y2 12x 8y 24 0

14

• Assignment1.5a p.49 (6-20even),p. 52-53(6abc,7,10-22even), p.998 (102,106)

• Assignment1.5b p.49 (22-36even, 50)