Question #d317a

1 Answer
Jan 27, 2018

#(x-a)^2+(y-b)^2=49/4#

Explanation:

Here, remember that the equation of a circle is like the following:
#(x-a)^2+(y-b)^2=r^2# where the center of the circle is #(a,b)# and #r# is the radius of the circle. #x# and #y# are the variables.

Since we are only given the diameter of a circle, we try to find the radius.
Remember that #d=2r#

Therefore, #2r=7#
=>#r=7/2#

We plug this into our standard form of #(x-a)^2+(y-b)^2=r^2#
=>#(x-a)^2+(y-b)^2=(7/2)^2#
=>#(x-a)^2+(y-b)^2=49/4#

That is our answer!

Now, this equation is telling us this: Any point that is #49/4# units away from the center #(a,b)# applies to the equation.