Equations of circles

Write the equation of a circle with center (7, 0) with radius 3.

• (x - 7)² + y² = 9

• x² + (y -7)² = 9

• (x - 7)² + y² = 3

• x² + (y -7)² = 3

What is the equation of the circle?

• (x+1)² + (y +1)² = 3

• (x+1)² + (y -1)² = 3

• (x+1)² + (y +1)² = 9

• (x-1)² + (y -1)² = 9

What is the radius of the circle

(x+7)²+(y-2)²=144?

• 7

• 12

• 24

• 144

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

• (x - 2)² + (y + 5)² = 36

• (x - 5)² + (y + 2)² = 6

• (x + 5)² + (y - 2)² = 36

• (x + 2)² + (y - 5)² = 6

What does (h,k) standard for in the standard circle equation?

• (h,k) is the center of the circle

• (h,k) is a point on the circle.

• (h,k) is the radius of the circle

• (h,k) is the diameter of the circle

In the circle represented by the equation (x-4)²+(y-3)²=25, the diameter is

• 10

• 3

• 5

• 25

What is the equation of the circle?

• (x+1)² + (y +1)² = 3
• (x+1)² + (y -1)² = 3
• (x+1)² + (y +1)² = 9
• (x-1)² + (y -1)² = 9

Which graph corresponds to

(x+2)²+ (y-3)²=36

• A

• B

• C

• D

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

• Multiply out
• expand
• factor
• complete the square

What is the radius of the given circle:
 x²+y²-10x+8y-23=0?

• 4
• 2
• 8