User talk:120.21.60.61

April 2022
Welcome to Wikipedia. Thank you for reverting your recent experiment&#32;with the page Directional derivative. Please take a look at the welcome page to learn more about contributing to our encyclopedia. If you would like to experiment further, please use the sandbox instead, as someone could see your edit before you revert it. Thank you. Adakiko (talk) 05:38, 29 April 2022 (UTC)