# Difference between curly derivatives and ordinary d derivatives, when to use each?

1. Nov 4, 2009

### roberto85

1. The problem statement, all variables and given/known data
The title says it all, what is the difference between the curly d used for derivatives and a normal d in derivatives. When do you know when to use each one? Thanks

2. Nov 4, 2009

### Sorry!

Re: Difference between curly derivatives and ordinary d derivatives, when to use each

Curly d is used for partial derivatives. Regular d is for a total derivative.

Partial derivatives are when treat one variable as a variable and keep the rest as constants ignoring the relationship between the variables.

Total derivatives are when you do the same as above but the relationship between variables remains.

3. Nov 4, 2009

### roberto85

Re: Difference between curly derivatives and ordinary d derivatives, when to use each

Thanks, i did remember the curly d being used alot in partial deriv's, but wasnt sure that was their sole use. Thanks for clearing it up