Home > INT2 > Chapter 10 > Lesson 10.2.2 > Problem10-68

10-68.

Describe each circle by stating the center and radius. Complete the square to rewrite the equation in part (b) in graphing form.

1. $(x + 5)^2 + y^2 = 10$

Recall the standard form for a circle:
$(x - h)^² + (y - k)^² = r^²$
where the point $(h, k)$ is the circle's center and $r$ is the radius.

1. $x^2 - 6x + y^2 - 2y - 5 = 0$

$(x - 3)^² + y^² - 2y = 5 + 9$

$(x - 3)^² + (y - 1)^² = 5 + 9 + 1$

Center: $(3, 1)$
Radius: $\sqrt{15}$