Quantcast

A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

LilySwan

  • one year ago

find dy/dx if (ax+cx^5)/kx^8

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

    a,c, and k are constants?

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

    yes

  3. micahwood50
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Just use quotient rule.

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

    got stucked at one point

  5. micahwood50
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \(\dfrac{d}{dx} \dfrac{f(x)}{g(x)} = \dfrac{f'(x)g(x) - f(x)g'(x)}{(g(x))^2}\)

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

    why can we solve the numerator part first

  7. micahwood50
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    treat constant as if they are just "number", and not variable.

  8. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    @LilySwan Did you have a problem with finding derivative of the top or the bottom? That is what you need to plug into @micahwood50 's formula. what do you mean solve the numerator? You shouldn't be solving. You should be differentiating it. What is the derivative of the top part of your fraction?

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

    for the upper part 5cx^4 +a

  10. micahwood50
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Right f'(x) = a+5cx^4

  11. micahwood50
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Can you find g'(x)?

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

    for the lower part it will be 8kx^7

  13. micahwood50
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Yep. So you have f(x) = ax+cx^5, f'(x) = a+5cx^4, g(x) = kx^8, g'(x) = 8kx^7 Just plug these in formula given above then simplify.

  14. micahwood50
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    Can you do it? @LilySwan

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

    trying wait

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

    i was told to use this formula \[\frac{ d }{ dx }(\frac{ u}{ v }) =\frac{ (v \frac{ du }{ dx })-(u \frac{ dv }{ dx }) }{ v^2 }\]

  17. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    same formula different notation

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

    ?

  19. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \[\dfrac{d}{dx} \dfrac{f(x)}{g(x)} = \dfrac{f'(x)g(x) - f(x)g'(x)}{(g(x))^2} \] if you want you can replace the f's with u's the g's with v's the ' things with d/dx and you have the same formula

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

    \[5cx^4+a.kx^8 - ax+cx^5. 8kx^7/(kx^8)^2\]

  21. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    \[\frac{(5cx^4+a)(kx^8)-(ax+cx^5)(8kx^7)}{(kx^8)^2}\] i think this is what you mean

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

    yes

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

    what should i be doing the next

  24. myininaya
    • one year ago
    Best Response
    You've already chosen the best response.
    Medals 1

    guess you could multiply things out on top and also use law of exponents on the bottom to simplify the bottom

  25. 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.