3. Consider the real Cartesian plane with the standard distance function, d = the square root of [(X2 - X) + (Y2 - Y1)]. Determine a corresponding coordinate system for the line / given by y = 2x + 3 (that is, a function f : / --> R such that for any two points P and Q on I, d(P, Q) |f(Q) f(P).) Show all of your calculations.