Circles

Write the equation of a circle with center (-4,6) and radius 5.

•  $\left(x+4\right)^2+\left(y-6\right)^2=25$ 

•  $\left(x-4\right)^2+\left(y+6\right)^2=5$ 

•  $\left(x-4\right)^2+\left(y+6\right)^2=25$ 

•  $\left(x+4\right)^2+\left(y-6\right)^2=5$ 

 $\left(x-1\right)^2+\left(y+2\right)^2=4$ 
What is the graph of the circle?

• Graph A (black circle)

• Graph B (green circle)

• Graph C (red circle)

• Graph D (blue circle)

 $\left(x-4\right)^2+\left(y-5\right)^2=36$  

Identify the center and radius of the circle.

• center (4,5) radius 6

• center (4,5) radius 36

• center (-4,-5) radius 6

• center (-4,-5) radius 36

Write the equation of a circle with center (-2,1) passing through the point (-5,3)

•  $\left(x+5\right)^2+\left(y-3\right)^2=13$ 

•  $\left(x+2\right)^2+\left(y-1\right)^2=13$ 

•  $\left(x+5\right)^2+\left(y-3\right)^2=-5$ 

•  $\left(x+2\right)^2+\left(y-1\right)^2=-5$ 

Write the equation of a circle with center (0,2) and radius 3.

•  $\left(x-1\right)^2+\left(y-2\right)^2=9$ 

•  $x^2+\left(y-2\right)^2=9$ 

•  $x^2+\left(y+2\right)^2=3$ 

•  $x^2+\left(y-2\right)^2=3$ 

 $\left(x+8\right)^2+y^2=100$  

Identify the center and radius of the circle.

• center (-8,0)   radius: 10

• center (8,0)   radius:100

• center (-8,1)   radius: 10

• center (8,1)  radius: 100