How do you write the equation for a circle with center (–7 –6) and radius 2?

1 Answer
Jun 6, 2016

Answer:

#(x+7)^2+(y+6)^2=4#

Explanation:

The general form for the equation of a circle is
#color(white)("XXX")(x-color(red)(a))^2+(y-color(blue)(b))^2=color(green)(r)^2#
where the circle's center is at #(color(red)(a),color(blue)(b))#
and the circle's radius is #color(green)(r)#

Substituting #(color(red)(-7),color(blue)(-6))# for #(color(red)(a),color(blue)(b))#
and color(green)(2)# for #color(green)(r)#

#color(white)("XXX")(x-(color(red)(-7)))^2+(y-(color(blue)(-6)))^2=color(green)(r)^2#

which can be simplified as:
#color(white)("XXX")(x+7)^2+(y+6)^2=4#