Integrating from - to + infinity

Click For Summary
SUMMARY

The integral ∫ (x = -∞ to +∞) x³e^(-αx²) dx evaluates to 0 due to the integrand being an odd function. In contrast, the integral ∫ (x = 0 to +∞) x³e^(-αx²) dx equals 1/α². This distinction is crucial for understanding the behavior of odd functions over symmetric limits, confirming that the integral over the entire real line cancels out to zero.

PREREQUISITES
  • Understanding of odd and even functions in calculus
  • Familiarity with definite integrals and their properties
  • Knowledge of exponential decay functions
  • Basic skills in evaluating improper integrals
NEXT STEPS
  • Study the properties of odd and even functions in calculus
  • Learn about improper integrals and their convergence criteria
  • Explore the Gamma function and its applications in integration
  • Investigate the use of substitution methods in evaluating integrals
USEFUL FOR

Students studying calculus, particularly those focusing on integration techniques, as well as educators looking to clarify concepts related to odd functions and improper integrals.

terp.asessed
Messages
126
Reaction score
3

Homework Statement


I am having trouble integrating ∫ (x = -∞ to +∞) x3e-αx2 dx part--is this 0 or 1/α2? And, could someone explain? I am pretty sure that, when

∫ (x =0 to +∞) x3e-αx2 dx = 1/α2

However, with x = -∞ to +∞, and the function of the equation being odd, I am lost.

Homework Equations


above

The Attempt at a Solution


above
 
Physics news on Phys.org
It's zero because, like you noted, the integrand is odd.
 

Similar threads

  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 105 ·
4
Replies
105
Views
11K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
Replies
4
Views
3K
Replies
9
Views
2K
Replies
2
Views
1K
Replies
5
Views
2K
  • · Replies 5 ·
Replies
5
Views
3K