How do you write an equation for a circle given center (-8,7) and radius is 1/2 units?

2 Answers
Jul 10, 2017

#(x+8)^2+(y-7)^2=1/4#

Explanation:

#"the standard form of the equation of a circle 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 the radius"#

#"here " (a,b)=(-8,7)" and " r=1/2#

#rArr(x-(-8))^2+(y-7)^2=(1/2)^2#

#rArr(x+8)^2+(y-7)^2=1/4" is the equation"#

Jul 10, 2017

#(x+8)^2 + (y-7)^2 = 1/4#

Explanation:

The standard form for an equation of a circle is given by

#(x-h)^2 + (y-k)^2 = r^2#

where

  • #h# is the #x#-coordinate for the center of the circle

  • #k# is the #y#-coordinate for the center of the circle

  • #r# is the radius of the circle

Plugging In known values, we have

#(x-(-8))^2 + (y-(7))^2 = (1/2)^2#

#color(red)((x+8)^2 + (y-7)^2 = 1/4#