Continuity of Dirichlet looking function

Click For Summary
SUMMARY

The function f(x) defined as f(x) = x for irrational x and f(x) = 0 for rational x is continuous only at irrational points. The function outputs 0 for all rational inputs, indicating that rational points are points of discontinuity. Therefore, the function is continuous at all irrational numbers and discontinuous at all rational numbers. This conclusion is based on the behavior of the function at different types of inputs.

PREREQUISITES
  • Understanding of continuity in real analysis
  • Knowledge of rational and irrational numbers
  • Familiarity with piecewise functions
  • Basic concepts of limits and discontinuities
NEXT STEPS
  • Study the properties of continuous functions in real analysis
  • Explore the concept of limits and their relation to continuity
  • Learn about piecewise function behavior and analysis
  • Investigate examples of functions with similar discontinuities
USEFUL FOR

Students of mathematics, particularly those studying real analysis, and educators looking for examples of continuity and discontinuity in functions.

daolian89
Messages
1
Reaction score
0

Homework Statement


Where is the function f(x) continuous?

f(x) =
x, if x is irrational

0, if x is rational




Homework Equations





The Attempt at a Solution

 
Physics news on Phys.org
The function gives 0 output (the Y axis) for all rational inputs and the input itself for irrational inputs. Then if I'm not wrong, the irrational points are points of discontinuity and the function is continuous everywhere else.
 

Similar threads

  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 27 ·
Replies
27
Views
2K
  • · Replies 20 ·
Replies
20
Views
3K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 40 ·
2
Replies
40
Views
5K
Replies
7
Views
2K
Replies
7
Views
2K
Replies
22
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
Replies
4
Views
3K