Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

wcaprar

  • 4 years ago

Need help on the next step of this definite integral

  • This Question is Closed
  1. wcaprar
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    \[\int\limits_{1}^{2} 3x/\sqrt{4x+5} dx\] I used the u-sub of sqrt{4x+5}, u^2=4x+5 got 2udu=4dx and then udu=2dx. I feel like the next step is right in front of my eyes but I'm just not seeing it

  2. dumbcow
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    when you sub in for dx, the u will cancel with the sqrt(4x+5) since it is equal to u replace x with (u^2 -5)/4 \[\rightarrow \frac{3}{8}\int\limits_{1}^{2}(u^{2}-5) du\]

  3. wcaprar
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Can I just pull the 3 out from the x like that?

  4. dumbcow
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    oh sorry i didn't see you responded yes you can, anytime it is a constant \[\int\limits_{?}^{?}n*x dx= n \int\limits_{?}^{?}x dx\]

  5. wcaprar
    • 4 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    np, gave me time to try to figure it all out, lol.

  6. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy