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

bigcat Group Title

find the derivative of f(x)=x^2 + x -3 using the definition of the derivative

  • one year ago
  • one year ago

  • This Question is Closed
  1. Callisto Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    \[f'(x)\]\[=\lim_{h \rightarrow 0}\frac{f(x+h) - f(x)}{h}\]\[=\lim_{h \rightarrow 0}\frac{[(x+h)^2 + (x+h) -3] -(x^2 + x -3)}{h}\]Can you simplify the fraction first?

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

    I used x^2 + 2(x)(h) + h^2 + x +h -3 -x^2 -x +3 = 2x + x ??

    • one year ago
  3. Callisto Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    x^2 + 2(x)(h) + h^2 + x +h -3 -x^2 -x +3 <- correct for denominator. But it's not equal to 2x + x... \[x^2 + 2(x)(h) + h^2 + x +h -3 -x^2 -x +3\]Group the like terms together: \[x^2 -x^2 + x -x -3 +3+ h^2+ 2(x)(h)+h\] Now, can you simplify the above expression

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

    basically factor out the h and H(h+2x+1) divided by the h on denominator and = h + 2x + 1?

    • one year ago
  5. Callisto Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    Yes.

    • one year ago
  6. Callisto Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    And you got: \[\lim_{h \rightarrow 0} (h+2x+1)\]Can you evaluate the limit?

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

    Would be 2x + 1 ??? Because h is going to 0

    • one year ago
  8. Callisto Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    Indeed it is!

    • one year ago
  9. bigcat Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    Holy Cow! It came together finally!! Thank you very much for your help! I would have been stuck!!!

    • one year ago
  10. Callisto Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    You're welcome :)

    • one year ago
  11. bigcat Group Title
    Best Response
    You've already chosen the best response.
    Medals 0

    Have a great day!!

    • one year ago
  12. Callisto Group Title
    Best Response
    You've already chosen the best response.
    Medals 3

    You too! :)

    • one year 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.