Quantcast

Got Homework?

Connect with other students for help. It's a free community.

  • across
    MIT Grad Student
    Online now
  • laura*
    Helped 1,000 students
    Online now
  • Hero
    College Math Guru
    Online now

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

gandalfwiz

Who wants a medal? Can you teach me about series and sequences?

  • 11 months ago
  • 11 months ago

  • This Question is Closed
  1. Jamal_Negrar
    Best Response
    You've already chosen the best response.
    Medals 1

    Taking the Calc BC test tomorrow? Anyway, I can probably say a few things. Firstly, Taylor Series: You can generate a taylor series centered at x = a for a function by f(x) + f'(x)(x-a) + f''(x)(x-a)^2/2! +... I think you get the idea. Usually these use f(0), f'(0), etc. but sometimes they will specify a different place to do it.

    • 11 months ago
  2. Jamal_Negrar
    Best Response
    You've already chosen the best response.
    Medals 1

    Now, on the note of convergence: The ratio test is your friend. Most convergence things can be done with by dividing the n+1th term by the nth term of the series. The series converges where the absolute value of that ratio < 1. Conditional convergence can occur where it = 1, you have to check for that other ways.

    • 11 months ago
  3. waterineyes
    Best Response
    You've already chosen the best response.
    Medals 0

    Are you talking about Arithmetic Progression, Geometric Progression, Harmonic Progression or the other series that Jamal is giving here? @gandalfwiz

    • 11 months ago
  4. Jamal_Negrar
    Best Response
    You've already chosen the best response.
    Medals 1

    1/(1-x) = 1 + x + x^2 + x^3 + ... + x^n where x < 1. You can substitute in (-x) for X to get 1/(1+x) = 1 - x + x^2 - ... + (-x)^n You can also integrate that series to get the ln(1+x) or -ln(1-x) depending on which one you integrate.

    • 11 months ago
  5. Jamal_Negrar
    Best Response
    You've already chosen the best response.
    Medals 1

    The series for sin(x) = X- X^3/3! + X^5/5! - ... + (-1)^nx^2n+1/(2n+1)! You can get the cosine series by taking the derivative of that or by using the taylor series formula I poster earlier. That's how you can derive the sin series if you can forget it.

    • 11 months ago
  6. Jamal_Negrar
    Best Response
    You've already chosen the best response.
    Medals 1

    The e^x series is just 1 + x + x^2/2! + ... +x^n/n!. Easy. Again, you can use the taylor series formula to get this.

    • 11 months ago
  7. Jamal_Negrar
    Best Response
    You've already chosen the best response.
    Medals 1

    Oh, I forgot to mention that the ratio test is the limit as n goes to infinity of the ratio I mentioned earlier. Stupid me.

    • 11 months ago
  8. gandalfwiz
    Best Response
    You've already chosen the best response.
    Medals 0

    Wait, before you go on Jamal, I'm not quite that advanced.

    • 11 months ago
  9. gandalfwiz
    Best Response
    You've already chosen the best response.
    Medals 0

    Sorry to let you go on for so long, but the site just let me load my question-- this is just for precalc.

    • 11 months ago
  10. Jamal_Negrar
    Best Response
    You've already chosen the best response.
    Medals 1

    Oh, lol, sorry. I just have the calc BC test tomorrow and I was studying this. Anything in particular I can help with? I'm not great at precalc, though.

    • 11 months ago
  11. gandalfwiz
    Best Response
    You've already chosen the best response.
    Medals 0

    Haha, I've got a lot of friends taking that tomorrow too. I was watching Khan academy and he filled in the questions I had. But thanks anyways! You still get a medal :)

    • 11 months ago
    • Attachments:

See more questions >>>

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.