Is There a Proof for Tabular Integration?

  • Thread starter Thread starter MadViolinist
  • Start date Start date
  • Tags Tags
    Integration Proof
Click For Summary
Tabular integration is a shortcut method for integration by parts, but it lacks a formal proof. It essentially serves as a shorthand for the traditional integration by parts process. By using placeholder functions for u and v, one can demonstrate that tabular integration yields the same results as the standard method. The method simplifies the process by organizing calculations visually with diagonal lines and alternating signs. Ultimately, tabular integration is a time-saving technique rather than a rigorously proven approach.
MadViolinist
Messages
18
Reaction score
0
Today we learned tabular integration as a shortcut method for integration by parts. Is there a proof that legitimizes tabular integration out there, or some general formula? Because there has to be some sort of logic for the process of creating the diagonal lines, or assigning pluses and minuses. Thanks in advance.
 
Physics news on Phys.org
There isn't really a proof for tabular integration, it's just shorthand for integration by parts. If you did a integration by parts using placeholder functions for u and v (meaning the actual functions could be whatever you want) you'll see that it expands to the same thing that tabular integration does, it just saves time doing by remembering the tabular way.
 
There are probably loads of proofs of this online, but I do not want to cheat. Here is my attempt: Convexity says that $$f(\lambda a + (1-\lambda)b) \leq \lambda f(a) + (1-\lambda) f(b)$$ $$f(b + \lambda(a-b)) \leq f(b) + \lambda (f(a) - f(b))$$ We know from the intermediate value theorem that there exists a ##c \in (b,a)## such that $$\frac{f(a) - f(b)}{a-b} = f'(c).$$ Hence $$f(b + \lambda(a-b)) \leq f(b) + \lambda (a - b) f'(c))$$ $$\frac{f(b + \lambda(a-b)) - f(b)}{\lambda(a-b)}...

Similar threads

  • · Replies 2 ·
Replies
2
Views
4K
  • · Replies 4 ·
Replies
4
Views
1K
  • · Replies 1 ·
Replies
1
Views
5K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
4K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 11 ·
Replies
11
Views
5K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K