TS EAMCET 4 May 2018 Shift 1 Solved Paper

Consider the given circle.
x2+y2−6x−2y+1=0
(x−3)2+(y−1)2=9
And the line y+c=0 is tangent to the circle at point (a,4)
So,
4+c=0
c=−4
The slope of line joining the point of contact and center is infinite.

a−3

4−1

=0
a−3=0
a=3
Therefore,
ac=(3)(−4)
=−12