x^2 - 10x + y^2 - 12y + 57 = 0
x^2 - 10x + 25 + y^2 - 12x + 36 = -57 + 25 + 36
(x - 5)^2 + (y - 6)^2 = 4
(x - 5)^2 + (y - 6)^2 = 2^2
This is the equation of the circle.
The line y = kx is a line that passes through the point (0, 0).
Between two values of k, t intersects the circle at 2 points.
The values of k are the calues that make the lines y = kx tangents to the circle.