text: function draw() {
    let canvas = document.getElementById("canvas");
    let ctx = canvas.getContext("2d");
    ctx.strokeStyle = "#FF0000";
  
    let valueFunction = new ValueFunction(6);
    let powerFunction = new PowerFunction(1);
    let addFunction = new AddFunction(powerFunction, valueFunction);
  
    let width = canvas.width;
    let height = canvas.height;
    let x = 0;
    let y = addFunction.evaluate(x);
    ctx.moveTo(x, height - y);
  
    for (x = 0; x < width; x += 0.1) {
      y = addFunction.evaluate(x);
      ctx.lineTo(x, height - y);
    }
  
    ctx.stroke();
  }