Fix reference to math.js

toroid.html

@@ -88,8 +88,8 @@
             </ul>
             </div>
         </section>
-        <!--script src="https://cdnjs.cloudflare.com/ajax/libs/mathjs/7.5.1/math.min.js"></script-->
+        <script src="https://cdnjs.cloudflare.com/ajax/libs/mathjs/7.5.1/math.min.js"></script>
-        <script src="math.js"></script>
+        <!--script src="math.js"></script-->
         <script src="inductor.js"></script>
         <script>
             function awgToMm(awg) {