What point on the line y= 9x + 4 is closest to the origin? Let D be the distance between the two points. What is the objective function in terms of the x coordinate? D= (Type an expression.) The interval of interest of the function is (Simplify your answer. Type your answer in interval notation.) The point on the line y= 9x + 4 closest to the origin is (Type an ordered pair. Simplify your answer. Type integers or simplified fractions.)