How to fix NotFoundHttpException laravel?

Hi all I am a new of laravel 5.1,I just start learning laravel. I have problame in laravel I can not find the way to correct it I try to search but I still can not.

And here is my code: CourseController.php

public function update(Request $request, $id)
    {
        $input = $request->all();
        $data = Course::findOrFail($id);
        $data->update($input);

        return redirect('course');
    }

and my model Course.php

<?php

namespace App;

use Illuminate\Database\Eloquent\Model;



class Course extends Model
{
    protected $table = "course";
    protected $primaryKey = "course_id";

    protected $fillable=[
    'course_title',
    'course_code',
    'course_credite'
    ];
}

And my route

Route::resource('course','CourseController');

via Chebli Mohamed