<?php include 'garrisonsmath.php'; $func = new GarrisonsMath(); $func->printDoMathPage(); if (!empty($_POST)) { $x = $_POST["x"]; $h = $_POST["h"]; $before = ($func->mathstuff($x + $h) - $func->mathstuff($x)) / $h; echo "before (((x+h)^2 + 7(x+h) + 2) - (x^2 + 7x + 2)) / h: = " . $before; echo "<br>after (2x + h + 7): = " . $func->simple($x, $h); }