Circle Equations and Properties

Mr. Kenan Ola explains how to graph a circle given its equation. He begins by reviewing the formula for a circle, derived from the Pythagorean theorem, and explains the significance of the radius and center coordinates (H, K). The video includes three examples, each demonstrating how to identify the center and radius from the equation, and how to plot the circle using a compass. The tutorial emphasizes the importance of correctly interpreting the equation's signs and provides tips for accurate graphing.

What is the formula for a circle derived from?

• Pythagorean theorem

• Trigonometric identities

• Quadratic equation

• Linear equation

In the circle equation, what do H and K represent?

• The circumference

• The radius

• The center

• The diameter

How do you adjust the equation if there is a plus sign in the circle formula?

• Write it as X plus

• Write it as X minus

• Write it as Y minus

• Write it as Y plus

What is the center of the circle if the equation is (X + 2)^2 + (Y - 1)^2 = 9?

• (2, -1)

• (-2, 1)

• (1, -2)

• (-1, 2)

What is the radius of the circle if the equation is (X + 2)^2 + (Y - 1)^2 = 9?

• 2

• 3

• 4

• 5

If there is no number next to the Y-term in the circle equation, what value does it represent?

• Negative one

• Zero

• One

• Two

What is the radius of the circle if the equation is (X - 1)^2 + Y^2 = 4?

• 1

• 2

• 3

• 4

How do you handle a negative value in the Y-term of the circle equation?

• Ignore it

• Write it as Y minus

• Write it as Y plus

• Write it as Y minus negative

What is the center of the circle if the equation is (X - 3)^2 + (Y + 2)^2 = 16?

• (-3, 2)

• (3, -2)

• (2, -3)

• (-2, 3)

What is the radius of the circle if the equation is (X - 3)^2 + (Y + 2)^2 = 16?

• 3

• 2

• 4

• 5