A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • one year ago

I'm trying to do question 11, p. 181. The answer is in the book, but I don't see how to get there.

  • This Question is Closed
  1. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Can you post a screen shot, photo, or type in the exact problem? (and their answer)

  2. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ydy/dx=x((y^4)+2y^2)+!). They want a particular solution for y=1 when x=4. The books's answer is y = sqrt(((2x^2)-31)/(33-2x^2)).

  3. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    is the problem \[ y \frac{dy}{dx} = x ( y^4 +2y^2 +1) \] ? If so, put the y's on one side and x on the other: \[ \frac{y}{y^4 +2y^2 +1} \ dy = x \ dx\] the denominator is a perfect square, so write it as \[ \frac{y\ dy }{(y^2+1)^2} = x \ dx\] or \[ \frac{1}{2}(y^2+1)^{-2} 2y \ dy = x \ dx\]

  4. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    notice if we let u= y^2+1 then du = 2y dy and the left side is equivalent to \[ \frac{1}{2} u^{-2} du \] which we can integrate

  5. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    ok, I do get the book's answer

  6. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Thank you, phi! I will try to finish now. You have been a great help! I had some of those ideas, but I could not quite put it all together. I hope I can get the rest of it on my own. Many thanks. I've been stewing over that problem for a while!

  7. anonymous
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    It took a while, but I got it. Your help got me unstuck. Thanks again!

  8. phi
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 0

    excellent

  9. 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

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.