How do you find the center and radius for # (x-2)^2+ (y+7)^2 =40#?
1 Answer
Aug 14, 2016
centre = (2 ,-7)
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.The equation here
#(x-2)^2+(y+7)^2=40" is in this form"# and by comparison : a = 2 , b = -7 and
#r^2=40#
#rArr" centre" =(2,-7)" and " r=sqrt40=2sqrt10#
