How do you find the center and radius of the circle with equation #(x-5)^2+(y+2)^2=15#?
1 Answer
Sep 3, 2016
centre = (5 ,-2), radius
Explanation:
The standard form of the equation of a circle is.
#color(red)(|bar(ul(color(white)(a/a)color(black)((x-a)^2+(y-b)^2=r^2)color(white)(a/a)|)))#
where (a ,b) are the coordinates of the centre and r, the radius.
#(x-5)^2+(y+2)^2=15" is in this form"# and by comparison with the standard form we obtain.
a = 5 , b = -2 and
#r^2=15#
#rArr" centre" =(5,-2)" and " r=sqrt15#
