What is the application of total derivative other than measure maxium error?

What is the application of total derivative other than measure maxium error?

reference(p.69-70)

Problems in the calculus: with ... - Google Books

Re: What is the application of total derivative other than measure maxium error?

Quote:

Originally Posted by

**victorlui**

Define 'application'.

Re: What is the application of total derivative other than measure maxium error?

i was just mean the total derivative was just approximate get the result,what makes it important?