Update 01-mp.md

Author: mikebarkmin

book/oberstufe/vorbereitung-abitur/01-mp.md

@@ -22,6 +22,7 @@ const f = board.create('functiongraph', [
   function (x) {
     return -0.25 * x ** 3 + 1.5 * x ** 2 + 1;
   },
+0,6,
 ], { strokeWidth: 2, strokeColor: '#007864' });
 
 board.create('point', [0, 1], { name: 'Start', size: 2, color: 'red', fixed: true });