Question: y = cx2 represents a one-parameter family of parabolas. Find the equation of another one-parameter family of curves with the property that at any point (x, y) where the curves from both families pass through the point, their tangent lines at this point are perpendicular to each other. (Show that the slope of the tangent lines at any point not on the y-axis to the original family of parabolas is 2y/x.)