Question

write an equation of the circle with the given center and radius (-10,7) r=2$\sqrt{?}$

Answer 1

The general equation of a circle is the following

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

where the point (h,k) is the center of the circle and r is the radius. In our case we have h=-10,k=7 and r=2. So we get

$(x-(-10))^2+(y-7)^2=2^2=4$

which is equivalent to

$(x+10)^2+(y-7)^2=4$