<?php

// your code goes here
$arr1 = array(
  0 => 'ultimoteste3',
  1 => 'ultimoteste3',
  2 => 'Rodrigues',
  3 => 'ultimoteste3@hotmail.com',
  4 => '2',
  5 => 'Teste Curso');
  
$arr2 = array(
  0 => 'username',
  1 => 'firstname',
  2 => 'lastname',
  3 => 'email',
  4 => 'lang',
  5 => 'course1',
  6 => 'type1',
  7 => 'auth');
  
  print_r(array_diff($arr1, $arr2));