Circles with Completing the Square

Change the following equation to standard form

x² + y² - 4x + 12y - 8 = 0

• (x + 2)² + (y - 6)² = 48

• (x - 2)² + (y + 6)² = 48

• (x - 6)² + (y - 2)² = 48

• (x + 2)² + (y + 6)² = 48

Determine the center and radius:

x² + y² + 8y - 10x = 8

• C = (5, -4) r = 7

• C = (-5, 4) r = 7

• C = (-4, 5) r = 49

• C = (5, -4) r = 49

What does the r in the standard equation stand for?

• r is the distance of the circle

• r is the radius of the circle

• r is the x coordinate of the center of the circle

• r is the y coordinate of the center of the circle

Tags

CCSS.HSG.GPE.A.1

Find the center and radius of the circle: 3x² + 3y² + 42x - 6y = -3

• center= (-7, 2) radius= 3

• center= (-7, 1) radius= 7

• center= (-4, 1) radius= 5

What is the equation of the circle, with center (a,b) and radius r units?

• (x - a)^2 + (y - b)^2 = r^2

• (x + a)^2 + (y + b)^2 = r^

• (x - a)^2 + (y - b)^2 = r^

• (x + a)^2 + (y + b)^2 = r^2

What numbers go in the blanks?

x² + y² + 14x - 2y = -1

x² + 14x + _____ + y² - 2y + _____= -1 + 50

• 7 and 1

• 49 and 1

• 14 and 1

• 49 and 2

Fill in the blank for the following problem:

x² + y² - 12x + 4y = -4

(x ² - 12x + 36) + (y² + 4y + 4) = - 4 + _____

(x - 6)² + (y + 2)² = 36

• 4

• 36

• 40

• 8

Change the following equation to standard form

x² + y² +12y = 8

• x² + (y + 6)² = 44

• x² + (y + 6)² = 8

• (x - 6)² + y² = 44

• x² + (y + 6)² = 14