Quantcast

A community for students. Sign up today!

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

ZeroAT

  • 2 years ago

Write an equation for the tangent line to f(x) = -4x + 3/x at x = -1 How do i solve this?

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

    So, we need to know the slope at this point, this is given by: \[ \frac{d}{dx}\left(-4x+\frac{3}{x}\right)=-4-\frac{3}{x^2} \]Evaluating this at \(x=-1\): \[ -4-\frac{3}{x^2}\Bigg|_{x=-1}=-4+3=-1 \]So the slope of the line is -1 at this point. Now, find a point on the line: \[ -4(-1)+\frac{3}{-1}=-7=y \]Which means: \[ y+7=-1(x+1) \]Et voilá.

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

    thank you.

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

    Which would be the correct answer: A) -7x + y = -6 B) -6x + 2y = -5 C) 7x + y = -6 D) 6x + 2y = -5

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

    Wait, I screwed up, it's: \[ -4-\frac{3}{x^2}\Bigg|_{x=-1}=-4-3=-7 \]So: \[ y+7=-7(x+1) \]

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

    oh! that explains why i coudnt get the answer. Thanks for the assistance

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

    Sure thing

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

    One more question..How would i get the end results in one of those 4 possible results i mentioned? can you show me?

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

    Just solve for the same form, it's roughly the same case.

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

    • Attachments:

Ask your own question

Ask a Question
Find more explanations on OpenStudy

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.