### Home > CCA2 > Chapter 3 > Lesson 3.1.3 > Problem3-54

3-54.

Give the equation of each circle below in graphing form. .

1. A circle with center $(0,0)$ and radius $6$.

Remember the general equation for a circle is $(x−h)^2+(y−k)^2=r^2$ where $(h,k)$ is the center.

2. A circle with center $(2,−3)$ and radius $6$.

See part (a).

3. A circle with equation $x^2+y^2−8x+10y+5=0$.

Complete the squares for $x$ and $y$.

Rearrange the equation:
$x^2−8x+$ _______ $+y^2+10y+$ _______ $=−5+$ _______ $+$ _______

$(x−4)^2+(y+5)^2=36$

Use the eTool below to graph the equations for each part.
Click the link at right for the full version of the eTool: CCA2 3-54 HW eTool