AnswersOH-Geometry BParallelograms

Equation of a Circle Answers

7 verified answers
1
Free Preview

What is the center of a circle represented by the equation (x+9)2+(y−6)2=102?

A
(−9,6)
B
(−6,9)
C
(6,−9)
D
(9,−6)
2
Free Preview

What is the radius of a circle whose equation is x2+y2+8x−6y+21=0?

A
2 units
B
3 units
C
4 units
D
5 units
3

Which equation represents a circle that contains the point (–5, –3) and has a center at (–2, 1)? Distance formula:

Question illustration
A
(x – 1)2 + (y + 2)2 = 25
B
(x + 2)2 + (y – 1)2 = 5
C
(x + 2)2 + (y – 1)2 = 25
D
(x – 1)2 + (y + 2)2 = 5
4

In the diagram, a circle centered at the origin, a right triangle, and the Pythagorean theorem are used to derive the equation of a circle, x2 + y2 = r2.

Question illustration
A
(h + x)2 + (k + y)2 = r2
B
(x – h)2 + (y – k)2 = r2
C
(k + x)2 + (h + y)2 = r2
D
(x – k)2 + (y – h)2 = r2
5

What is the center of a circle whose equation is x2 + y2 + 4x – 8y + 11 = 0?

A
(–2, 4)
B
(–4, 8)
C
(2, –4)
D
(4, –8)
6

On a coordinate plane, a circle has a center at (4, 5) and a radius of 3 units.

Question illustration
A
(x – 4)2 + (y – 5)2 = 2
B
(x – 4)2 + (y – 5)2 = 4
C
(x – 5)2 + (y – 4)2 = 2
D
(x – 5)2 + (y – 4)2 = 4
7

A sprinkler is designed to water a circular area that has a radius of 7 feet. The sprinkler is located at (0,0) on a lawn. A flowerbed is planted 3 feet east and 6 feet south of the sprinkler.Determine if the distance from the flowerbed to the sprinkler places the flowerbed on or within the circular area that this sprinkler can water.

A
No. The flowerbed is 18 feet away from the sprinkler, which is more than the 7-foot radius.
B
Yes. The flowerbed is exactly 7 feet away from the sprinkler.
C
No. The flowerbed is 9 feet away from the sprinkler, which is more than the 7-foot radius.
D
Yes. The flowerbed is √45 feet away from the sprinkler, which is less than the 7-foot radius.

Did you find these answers helpful?

More from this Course

Quiz
10 verified answers

4.4 - Volume of Pyramids

Quiz
10 verified answers

4.5 - Volume of Cylinders, Cones, and Spheres

Quiz
10 verified answers

4.6 - Cavalieri's Principle and Volume of Composite Figures

Equation of a Circle Answers — OH-Geometry B