Equations of Circles

Front

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

Back

(h,k) is the center of the circle.

Tags

CCSS.HSG.GPE.A.1

Front

What is the standard equation of a circle?

Back

(x-h)² + (y-k)² = r², where (h,k) is the center and r is the radius.

Tags

CCSS.HSG.GPE.A.1

Front

What does the r in the standard equation stand for?

Back

r is the radius of the circle.

Tags

CCSS.HSG.GPE.A.1

Front

What is the radius of the circle with the equation (x-5)²+(y+7)²=8?

Back

2√2

Tags

CCSS.HSG.GPE.A.1

Front

What is the center of the circle in the equation (x-3)²+(y+4)²=16?

Back

(3,-4)

Tags

CCSS.HSG.GPE.A.1

Front

How do you find the radius from the equation (x+2)²+(y-1)²=25?

Back

The radius is √25 = 5.

Tags

CCSS.HSG.GPE.A.1

Front

What is the equation of a circle with center (0,0) and radius 3?

Back

x² + y² = 9.

Tags

CCSS.HSG.GPE.A.1

Front

If a circle has a center at (2, -3) and a radius of 4, what is its equation?

Back

(x-2)² + (y+3)² = 16.

Tags

CCSS.HSG.GPE.A.1

Front

What is the distance formula used to find the distance between two points (x1, y1) and (x2, y2)?

Back

d = √((x2 - x1)² + (y2 - y1)²).

Tags

CCSS.HSG.GPE.B.7

Front

What is the general form of a circle's equation?

Back

x² + y² + Dx + Ey + F = 0.

Tags

CCSS.HSG.GPE.A.1