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Pearson Algebra 2 Common Core, 2011

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Pearson Algebra 2 Common Core, 2011 View details

4. Ellipses

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Exercise 68 Page 644

What is the standard form of a circle's equation?

(x+2)^2+(y-4)^2=81

Practice makes perfect

Let's start by recalling the standard form of a circle's equation.

(x- h)^2+(y- k)^2= r^2 In this form, ( h, k) is the center of the circle and r is its radius. We are told that the center of the circle is ( - 2, 4) and its radius is 9. This information is enough to write the equation. (x-( - 2))^2+(y- 4)^2= 9^2 ⇕ (x+2)^2+(y-4)^2=81

Subchapter links

Lesson Check p.642

Practice and Problem-Solving Exercises p.642-644

Standardized Test Prep p.644

Mixed Review p.644