PLEASE HELP
A circle is centered at the point (5, -4) and passes through the point (-3, 2).
The equation of this circle is (x + ? )2 + (y + ? )2 = ?

Question

PLEASE HELP
 A circle is centered at the point (5, -4) and passes through the point (-3, 2).
The equation of this circle is (x + ?  )2 + (y + ? )2 = ?

mhchen · Answer

Think about what the equation of the circle is. Think about how to find the radius of the circle given 2 points. Think about using the distance formula. Is the radius in the circle formula?

mathmale · Answer

You could either derive the equation of a circle centered at (h,k) with radius r from the distance formula, or you could learn and remember that equation of a circle.

That standard equation is $$(x-h)^2+(y-k)^2=r^2$$  and here the coordinates of the center are known, as are the coordinates of one point on the circle itself, i. e., (x, y).  This is all the info you need to determine r^2 and r.