two lines 5x-12 y=10 and 5x-12y=40 touches a circle C1 of diameter 6 if the centre of C1 lies in the first quadrant , find the equation of the circle C2 which is concentric with C1 and cuts intercepts of length 8 on these lines

in your question no circle with the given diameter can touch both the given lines
Thanks and Regards,
M.MURALIKRISHNA
askIITians faculty

Distance between 2 parallel lines (in this case the given lines) is given by : (c1-c2) / (a^2+b^2)^1/2 [where c1 and c2 are constants]. In this case the distance between the parallel lines is 30/13 which is unequal to 6. That is why the circle c1 is not possible.