# How do you find the center and radius of a circle using a polynomial #(x - 3) ^2 + (y + 4) ^2 = 25#?

##### 1 Answer

Apr 30, 2018

#### Explanation:

#"the equation of a circle in standard form is"#

#color(red)(bar(ul(|color(white)(2/2)color(black)((x-a)^2+(y-b)^2=r^2)color(white)(2/2)|)))#

#"where "(a,b)" are the coordinates of the centre and r"#

#"is the radius"#

#(x-3)^2+(y+4)^2=25" is in this form"#

#"with centre "=(3,-4)" and radius "=sqrt25=5#