gaussian regarding random variables

what would be the pictorial difference of PDFs of X1 and Y = X1- X2 where X1 and X2 are gaussian random variables. I am getting error in the code. can someone please help me .

[dpb]

Well, we certainly can't comment much on any error given no code and not even the error message to look at...

[Gargi Patil]

Can you please provide further details about your query including the error message being encountered? Thanks