Question 981394
The center will be half way between these two, so the average of the x=1 (-4+6)/2 and the y will be (-3)
Center is (1,-3)
The distance between these two points, using the distance formula, is sqrt (100+4).  The radius is (1/2) sqrt (104).

The equation of a circle in general is x^2+y^2=r^2;;r^2={(1/2)sqrt (104)}^2

Here, it is (x-1)^2+(y+3)^2=(1/4)*104
(x-1)^2+(y+3)^2)=26

Center will be (1,-3), radius is sqrt (26); diameter is 2sqrt(26), which is also sqrt(104).