length of y intercept on positive y axis made by the circle for which (-4,3) and (12,-1) are extremities of a diameter

Dear student 

Dear Student, 
The center will be ((−4+12)/2,(3−1)/2)= (4,1)
and radius diameter will be =sqrt((−4−12)^2+(3+1)^2) = 272
So radius = √272/2
So equation is (x−4)^2+(y−1)^2= 272/4= 68
Now if it cuts y axis then x = 0 
16+(y−1)2=68
 y −1 = √(68−16)= √52
So y = 2√13 +1
Regrads