Inside Outside on the Circle Circle Equations

Determine which point lies on the circle with equation x²+y²=49

• (√11,3)

• (0,-7)

• (-4, √13)

• (8,0)

Does the point (4,5) lie on the circle whose center is (-2,-2) and radius 9?

• yes

• No

How do you determine if a point is inside the circle?

• See if value after substitution for (x, y) = r²

• See if value after substitution for (x, y) > r²

• See if value after substitution for (x, y) < r²

A meteorite damaged a portion of a farm expressed by the equation (x - 6)² + (y - 7)² = 16. Which item on the farm was not damaged by the meteorite?

• The Silo located at
  (2, 4)

• The Barn located at
  (4, 6)

• The Pigpen located at
  (8,9)

Prove or disprove that the point (8,-3) lies on the circle centered at (-4,3) and has a radius of 13.

• (8,-3) lies on the circle

• (8,-3) lies outside the circle

• (8,-3) lies inside the circle

Prove or disprove that the point (3,7) lies on the circle centered at the origin and has a radius of 8.

• (3,7) lies on the circle

• (3,7) lies outside the circle

• (3,7) lies inside the circle

The equation (x+3)²+(y-5)²=r² represents circle A. The point B(0,6) lies on the circle. What is r, the length of the radius of circle A?

• √13

• 2

• 10

• √10

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 a point that we guess and find

• (h,k) is the distance of the circle

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

Write an equation of a circle in standard form if the center is located at (0, -2) and the radius is √3 (square root of 3).

• x² + (y - 2)² = 3

• x² + (y - 2)² = 9

• x² + (y + 2)² = 3

• (x - 1)² + (y - 2)² = 9