Circles and Ellipses

What is the standard equation of a circle?

• (x-k)² + (y-h)² = r²

• (x+h)² + (y+k)² = r²

• (x-h)² + (y-k)² = r²

• (k-x)² + (h-y)² = r²

What does (h,k) stand 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 a point that we guess and find

• (h,k) is the distance of the circle

In the equation (x-3)²+(y+4)²=121, the radius of the circle is

• 242
• 11
• 121
• 22

What is the equation of a circle with radius 2 and center (3, 4)?

• (x+3)² + (y+4)² = 2
• (x-3)² + (y-4)² = 2
• (x+3)² + (y+4)² = 4
• (x-3)² + (y-4)² = 4

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 are 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

In the equation (x-3)²+(y-2)²=16, the center of the circle is...

• (3,2)
• (-3, -2)
• (-2, -3)
• (2, 3)

• (x - 1)² + (y + 2)² = 2

• (x + 2)² + y² = 4

• x² + (y + 2)² = 4

• x² + (y + 2)² = 2

The major axis is:

• The shorter axis of an ellipse
• The longer axis of an ellipse
• The closest point closest to the Sun
• The farthest point closest to the Sun

What is the center of the ellipse?

• (0, 0)
• (1, 5)
• (1, 0)
• (0, 1)