derivative1
![derivative1](https://user-images.githubusercontent.com/61246381/87973783-aeabb980-cae6-11ea-8b7a-e0dd089ebf09.gif)

derivative2
![derivative2](https://user-images.githubusercontent.com/61246381/87973861-c5eaa700-cae6-11ea-87e7-4915d68ab04f.gif)

derivative3
![derivative3](https://user-images.githubusercontent.com/61246381/87973900-d69b1d00-cae6-11ea-9459-c51564dbc35d.gif)