How do you write an equation of a circle with center at (0,5), d=20?

2 Answers
Apr 18, 2018

Assuming #d# is the radius, the answer is # x^2 + (y-5)^2 = 20^2#

Explanation:

I'm not sure what #d# is here, let's assume it's the radius.

The general equation of a circle with center #(a,b)# and radius #r# is

#(x - a)^2 + (y-b)^2 = r^2#

So in our case that's

# (x - 0)^2 + (y - 5)^2 = 20^2 #

# x^2 + (y-5)^2 = 400#

Apr 18, 2018

#x^2+(y-5)^2=100#

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"#
#"is the radius"#

#"here "(a,b)=(0,5)" and r=d/2=20/2=10#

#rArr(x-0)^2+(y-5)^2=10^2#

#rArrx^2+(y-5)^2=100larrcolor(red)"equation of circle"#