A particle moves along y=xy = \sqrt{x}y=x. At what point does the normal line pass through (4,0)(4, 0)(4,0)?
(1,1)(1, 1)(1,1)
(2,2)(2, \sqrt{2})(2,2)
(4,2)(4, 2)(4,2)
(0,0)(0, 0)(0,0)