My confusion about ##u## and ##\mu##

  • B
  • Thread starter docnet
  • Start date
  • #1
docnet
587
242
TL;DR Summary
Are ##u## and ##\mu## used interchangeably in partial differential equations?
Hi all, I am confused about symbols.

I cannot figure out why my partial differential equations professor writes ##u## and ##\mu## in his lectures. A function ##u(x, y)## turns into ##\mu(x, y)##. His homework sets are always typed with ##u##. I also think he says MYOO during the lectures so it is not just a strange way to write ##u##. He is a Frenchman.

Screen Shot 2021-01-31 at 2.43.15 AM.png
 

Answers and Replies

  • #2
fresh_42
Mentor
Insights Author
2022 Award
17,643
18,302
##u## and ##\mu## are two very different letters, not only because one is Latin and the other one is Greek, but also because ##\mu ## is the Greek ##m##. I cannot find any ##\mu## in your photo above, and I think it is more a case of sloppy handwriting than it is a case of interchanging the two. However, there are some conventions: ##u## is normally a function, ##\mu## is either an index or a measure. This means that ##\int u\,d\mu## makes sense. But as with all conventions, this is no rule and everybody can use it in a different way.
 
  • Like
Likes docnet and sysprog
  • #3
pbuk
Science Advisor
Homework Helper
Gold Member
4,026
2,360
@fresh_42 is right - this is sloppy handwriting. The same error can be seen in the 'y' characters, particularly in the last line (the second one in ## f(y) ## is almost unrecognisable).

Note that outside a mathematical context the prefix 'micro-' which is properly abbreviated ## \mu ## is sometimes represented by a 'u' when limited to characters of the Latin alphabet: 1 min = 60 s = 60,000 ms = 60,000,000 us.
 
Last edited:
  • Like
Likes docnet and sysprog

Suggested for: My confusion about ##u## and ##\mu##

Replies
3
Views
295
Replies
7
Views
497
  • Last Post
Replies
2
Views
328
Replies
16
Views
501
Replies
4
Views
634
  • Last Post
Replies
6
Views
298
  • Last Post
Replies
5
Views
557
Replies
1
Views
457
Replies
1
Views
418
Top