In a MuPAD® notebook, you can convert characters in the text region to Greek letters one at a time:
Select the character you want to convert or place the cursor to the right of the character.
Select Edit>Toggle Greek.
For example, display the Greek letter δ by typing
then placing your cursor to the right of
selecting Edit>Toggle Greek.
To get the original font style use the same steps.
To use Greek letters in string input, enter them in a text region and copy them into the string.
To use Greek letters in code, see