Solving Indefinite Integrals: ∫1/(t*ln(t)) & ∫1/(√(t)*[1-2*√(t)])

In summary, the conversation involved using u-substitution to solve two integration problems, but the answers were marked as incorrect. However, upon checking with an online tool, it was found that the solutions were actually correct.
  • #1
Justabeginner
309
1

Homework Statement


[itex] ∫1/(t*ln(t)) dt [/itex]

[itex] ∫1/(√(t)*[1-2*√(t)]) dt [/itex]


Homework Equations





The Attempt at a Solution



I used u-substitution for both. For the first equation, my u= ln t, and my final answer was ln|u| + C, or ln(ln(|t|) + C. For the second equation, my u= 1-2*√(t) and my final answer was -ln(u) or -ln(1-2*√(t)) + C.

But both of these are wrong, so I'm not sure what I did wrong. Can I get some guidance on this? Thank you. :)
 
Physics news on Phys.org
  • #2
Justabeginner said:

Homework Statement


[itex] ∫1/(t*ln(t)) dt [/itex]

[itex] ∫1/(√(t)*[1-2*√(t)]) dt [/itex]


Homework Equations





The Attempt at a Solution



I used u-substitution for both. For the first equation, my u= ln t, and my final answer was ln|u| + C, or ln(ln(|t|) + C. For the second equation, my u= 1-2*√(t) and my final answer was -ln(u) or -ln(1-2*√(t)) + C.

But both of these are wrong, so I'm not sure what I did wrong. Can I get some guidance on this? Thank you. :)

Both of those are correct as far as integration goes. Must be an error in the answering system.
 
  • #3
Oh wow, that makes me feel better now. Thank you! :)
 
  • #5
Thank you! That site helps.
 

FAQ: Solving Indefinite Integrals: ∫1/(t*ln(t)) & ∫1/(√(t)*[1-2*√(t)])

1. How do I solve indefinite integrals involving logarithmic functions?

To solve indefinite integrals that involve logarithmic functions, you can use the substitution method. This involves substituting the variable in the integral with a new variable, simplifying the integral, and then solving for the original variable. In the case of ∫1/(t*ln(t)), you can let u = ln(t) and simplify the integral to ∫1/u du, which is equal to ln(u) + C. Then, substitute back in the original variable to get ln(ln(t)) + C.

2. Can indefinite integrals with square roots be solved using the substitution method?

Yes, indefinite integrals with square roots can also be solved using the substitution method. In the case of ∫1/(√(t)*[1-2*√(t)]), you can let u = √(t) and simplify the integral to ∫1/(u*[1-2u]) du. This can then be solved using partial fractions or other methods to get the final answer.

3. Are there any other methods for solving indefinite integrals involving logarithmic functions?

Yes, there are other methods for solving indefinite integrals involving logarithmic functions, such as integration by parts and using tables of integrals. However, the substitution method is often the most efficient and straightforward method for these types of integrals.

4. Can I use a calculator to solve indefinite integrals?

While some calculators may have the capability to solve indefinite integrals, it is important to understand the steps and methods involved in solving these types of integrals by hand. This will not only help you understand the concept better, but also allow you to check your answers and catch any mistakes.

5. Are there any tips for solving tricky indefinite integrals involving square roots?

One tip for solving tricky indefinite integrals involving square roots is to try to simplify the integral before applying the substitution method. This may involve factoring the denominator or using trigonometric identities to simplify the expression. You can also try different substitution variables to see if one leads to a simpler integral. It may also be helpful to practice solving various types of indefinite integrals to become more familiar with the methods and techniques involved.

Similar threads

Replies
3
Views
902
Replies
14
Views
1K
Replies
1
Views
1K
Replies
2
Views
968
Replies
3
Views
1K
Replies
2
Views
1K
Back
Top