Write the equation of the circle centered at 01 that passes

Write the equation of the circle centered at (0,1) that passes through (9,4).

Equation of circle centred at (0,-1) is

(x-0)^2/r^2 +(y-(-1))^2)/r^2=1

x^2/r^2+(y+1)^2/r^2=1
substitute (9,4)in above

81/r^2+25/r^2=1

r^2=106

So equation of circle is

x^2 +(y+1)^2=106

Thank you