A circle has radius sqrt(10)/2 and pass through A(1,1).A line y = 3x - 7 pass through the centre of the circle.Find the equation of the circle? Here is my attempt 
h = 3k -7 ----(1)
(h-1)^2 + (k -1)^2 = 10/4
(h-1)^2 + (3h - 8)^2 = 10/4
This second one doesn't working.Is my approch wrong?
P.S: Sorry for the typo.Also I assumed the center is C(h,k)

We want to find the point a distance of $\sqrt{10}/2$ on the line we are given from the point we are given. 
$$(x-1)^2+(3x-8)^2=5/2$$
$$10x^2-50x+65=5/2$$
$$x^2-5x+6.25=0$$
The point is therefore
$$x=5/2$$
$$y=1/2$$
This is the only such point, since the equation only has one root, therefore it is the center of the circle. Thus the equation of the circle is
$$(x-5/2)^2+(y-1/2)^2=5/2$$
