AP EAMCET Engineering 17 Sep 2020 Shift 2 Paper

For a tangent, length of perpendicular from origin = radius.
So we check distance from (0,0) and for any tangent it must be √10.
For 3x+y=10 and x−3y=10
Distance of (0,0) from line 3x+y=10 is,
Also from x−3y=10
d=|‌

0−3×0−10

√32+12

|=√10
So, option (c) is correct.