Can someone give me an intuitive definition for differentials?

Click For Summary
SUMMARY

Differentials represent the change in a function's linear approximation as a variable changes. Specifically, for a function f(x), the differential dy is defined as dy = f '(x) dx, where dx is an infinitesimally small change in x. This concept is crucial for understanding calculus and thermodynamics, as it relates to the family of tangent lines to the curve y = f(x). Recommended readings include Tenenbaum and Pollard's "Ordinary Differential Equations" and Loomis and Sternberg's text, particularly chapter 3, section 5.

PREREQUISITES
  • Understanding of basic calculus concepts, including derivatives
  • Familiarity with linear approximations and tangent lines
  • Knowledge of functions and their graphical representations
  • Basic reading comprehension of mathematical texts
NEXT STEPS
  • Study the concept of linear approximation in calculus
  • Read Tenenbaum and Pollard's "Ordinary Differential Equations" for foundational knowledge
  • Explore Loomis and Sternberg's text, focusing on chapter 3, section 5
  • Practice problems involving differentials and their applications in thermodynamics
USEFUL FOR

Students preparing for calculus and thermodynamics, particularly those seeking a practical understanding of differentials and their applications in mathematical modeling.

Howers
Messages
443
Reaction score
5
Can someone give me an intuitive definition for differentials? My prof said to brush up on them because we'll be seeing them lots in thermo. I don't need all the theory because I'll be seeing them in november in calc. Right now I just have to work with them. Are they just infinitely small differences?
 
Physics news on Phys.org
read tenenbaum and pollard, ode, first few pages.
 
This picture show what differential is for a function f(x)
http://www.bymath.com/studyguide/ana/sec/ana4a.gif
Basically, it is the change in the linear approximation for a function for a change in x, dx.

dy/dx = f '(x) -> differential dy = f '(x) dx
When dx is small dy is a good approximation for f(x + dx) - f(x);
 
consider for a smooth curve y=f(x), its family of tangent lines. the differential of f, df, is the family of linear functions whose graphs are those tangent lines.

so that picture depicted the graph of df(x0), the graph of one of the linear functions making up the differential.
 
Howers said:
Can someone give me an intuitive definition for differentials? My prof said to brush up on them because we'll be seeing them lots in thermo. I don't need all the theory because I'll be seeing them in november in calc. Right now I just have to work with them. Are they just infinitely small differences?

Loomis and Sternberg, chapter 3 section 5 and following sections.
You'll have to do some preliminary reading in order to get to this point. Their text is freely available.

Even if you don't do more than look at it now, it'll serve you well in November.
 

Similar threads

  • · Replies 7 ·
Replies
7
Views
4K
  • · Replies 53 ·
2
Replies
53
Views
6K
  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 22 ·
Replies
22
Views
3K
  • · Replies 23 ·
Replies
23
Views
2K
  • · Replies 18 ·
Replies
18
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 9 ·
Replies
9
Views
5K