Equations of Circles

What is the equation of a circle with radius 4 and center (0, 8)?

• x² + (y-8)² = 16

• (x-8)² + y² = 4

• x² + (y-8)² = 4

• x² + (y+8)² = 16

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

• (1, 1)

• (0, 0)

• not enough information

See Picture

• A

• B

• C

• D

In the equation (x+2)²+(y-3)²=4, the radius of the circle is...

• 4

• 2

• 3

• 16

The endpoints of a diameter of a circle are (3,1) and (9,5).Find the equation of the circle?

• (x−6)²+(y−3)²=13

• (x−3)²+(y−6)²=13²

• (x−5)²+(y−9)²=13

• (x−9)²+(y−5)²=169/4

Write the standard equation of the circle with the given center and radius; center (0,0) and radius: 3

• x²+y²=3

• x²+y²=6

• x²+y²=9

Which graph corresponds to 
(x)²+ (y-6)²=9

• A

• B

• C

• D

Determine the equation of the circle in standard form: x² + y² + 6x - 12y + 20 = 0

• (x-3)² + (y+6)² = 25

• (x+3)² + (y-6)² = 25

• (x-3)² + (y+6)² = 45

• (x+3)² + (y-6)² = 5

Determine the equation of the circle in standard form:
x² + y² + 4x + 6y - 36 = 0

• (x+2)² + (y+3)² = 49

• (x+2)² + (y+3)² = 13

• (x-2)² + (y-3)² = 49

• (x-2)² + (y-3)² = 13

Determine the equation of a circle with center (5,-3) and radius of 9

• x²+y²-10x+6y-47=4

• x²+y²-10x-6y-47=0

• 2x²+y²+10x+6y-47=0

• x²+y²-10x+6y-47=0