MathDB
Lattice Points on a Parabola

Source: 2014 AMC 12A #25

February 5, 2014
conicsparabolacalculusderivativevectoranalytic geometryparameterization

Problem Statement

The parabola PP has focus (0,0)(0,0) and goes through the points (4,3)(4,3) and (4,3)(-4,-3). For how many points (x,y)P(x,y)\in P with integer coefficients is it true that 4x+3y1000|4x+3y|\leq 1000?
<spanclass=latexbold>(A)</span>38<spanclass=latexbold>(B)</span>40<spanclass=latexbold>(C)</span>42<spanclass=latexbold>(D)</span>44<spanclass=latexbold>(E)</span>46<span class='latex-bold'>(A) </span>38\qquad <span class='latex-bold'>(B) </span>40\qquad <span class='latex-bold'>(C) </span>42\qquad <span class='latex-bold'>(D) </span>44\qquad <span class='latex-bold'>(E) </span>46\qquad