Graph Circle from the Equation Center Radius Form

The diameter of a circle has length 12. The center is at (-5, 2). Give the equation of the circle.

• (x + 5)² + (y - 2)² = 144

• (x - 5)² + (y + 2)² = 36

• (x + 5)² + (y - 2)² = 36

• (x - 5)² + (y + 2)² = 12

The point (3,3) is on a circle whose center is at (-1,3). Write the standard form of the equation of the circle.

• (x-3)²+(y-3)²=4

• (x-3)²+(y-3)²=16

• (x+1)²+(y-3)²=9

• (x+1)²+(y-3)²=16

What is the center and radius given the equation, x² + y² + 8x - 2y - 64 = 0?

• Center: (-4, 1), Radius: 9

• Center: (4,1), Radius: 8

• Center: (1,-4), Radius: 64

• Center: (-4, 1), Radius: 81

What is the center of the circle with equation x² + y² = 1?

• (1, 1)

• (0, 0)

• (0,1)

• not enough information

• (x - 1)² + (y + 2)² = 2

• (x + 2)² + y² = 4

• x² + (y + 2)² = 4

• x² + (y + 2)² = 2

In order to convert from general form to center-radius form, you must ___________. 

• Multiply out

• expand

• factor

• complete the square

What is the coordinates of the center and the radius of the circle with equation:

(x - 4)^2 + (y - 3)^2 = 25^ ?

• Center (4,3)

  Radius = 5 units

• Center (4,3)

  Radius = 25 units

• Center (-4,-3)

  Radius = 25 units

• Center (-4,-3)

  Radius = 5 units

See Picture

• A

• B

• C

• D

What is the coordinates of the center and the radius of the circle with equation:

(x - 1)^2 + (y - 2)^2 = 3^2 ?

• Center (-1,-2)

  Radius = 3 units

• Center (1,2)

  Radius = 3 units

• Center (-1,-2)

  Radius = 9 units

• Center (1,2)

  Radius = 9 units

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