Equating integrands on two equal integrals?

  • Thread starter russdot
  • Start date
  • Tags
    Integrals
In summary, the conversation discusses whether it is valid to equate the integrands if two different integrals have the same value. The equations and attempt at a solution provided suggest that this may not be valid. The example of integrals with different integrands but the same value is given to demonstrate this.
  • #1
russdot
16
0

Homework Statement


This is more of a general question. If I have two different integrals that equal the same value, is it valid to equate the integrands?

Homework Equations


[tex]\int P(\theta,\phi)d\Omega = N[/tex]
[tex]\int Q(\theta',\phi')d\Omega' = N[/tex]
Where [tex]N[/tex] is a constant and [tex]d\Omega = sin\theta d\theta d\phi[/tex]

The Attempt at a Solution


Since it can be said:
[tex]\int Q(\theta',\phi')d\Omega' = N = \int P(\theta,\phi)d\Omega[/tex]

Is it valid to conclude that
[tex]Q(\theta',\phi')d\Omega' = N = P(\theta,\phi)d\Omega[/tex] ?

Thank you.
 
Physics news on Phys.org
  • #2
The integral from 0 to 1 of f(t)=t dt is 1/2. The integral from 0 to 1 of f(t)=(1/2) dt is also 1/2. No, you can't equate the integrands.
 
Last edited:

1. How do you equate integrands on two equal integrals?

To equate integrands on two equal integrals, you must first identify the integrands on each integral. Then, set the two integrands equal to each other and solve for the variable of integration.

2. What is the purpose of equating integrands on two equal integrals?

The purpose of equating integrands on two equal integrals is to compare and evaluate the functions being integrated in both integrals. This can help in solving complex integrals or finding relationships between two functions.

3. Are there any limitations to equating integrands on two equal integrals?

Yes, there are limitations to equating integrands on two equal integrals. This method can only be used for integrals with the same limits of integration and variables of integration. It also assumes that the integrands are continuous and differentiable.

4. Can equating integrands on two equal integrals be used for definite integrals?

Yes, equating integrands on two equal integrals can be used for definite integrals as long as the limitations mentioned above are met. This method is commonly used in solving definite integrals with trigonometric functions.

5. How does equating integrands on two equal integrals relate to the Fundamental Theorem of Calculus?

The Fundamental Theorem of Calculus states that the integral of a function can be evaluated by finding its antiderivative and evaluating it at the limits of integration. Equating integrands on two equal integrals uses this principle to equate the integrands and solve for the variable of integration, thus creating a relationship between the two functions being integrated.

Similar threads

  • Calculus and Beyond Homework Help
Replies
3
Views
557
  • Calculus and Beyond Homework Help
Replies
4
Views
133
  • Calculus and Beyond Homework Help
Replies
2
Views
1K
  • Calculus and Beyond Homework Help
Replies
9
Views
958
  • Calculus and Beyond Homework Help
Replies
5
Views
2K
  • Introductory Physics Homework Help
Replies
17
Views
395
Replies
3
Views
1K
  • Calculus and Beyond Homework Help
Replies
22
Views
1K
  • Special and General Relativity
Replies
5
Views
356
  • Calculus and Beyond Homework Help
Replies
3
Views
2K
Back
Top