A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 5 years ago

If y=|cos x| then f'(3pi/4) is?

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

    \[\frac{-1}{\sqrt{2}}\]

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

    it should be +ve 1/root2

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

    no, i don't think

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

    the slope of the tangent is negative at the reqd point in the graph of f(x)=|cosx|

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

    sorry, its 1/rt(2). u r right.

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

    ok how did you get it

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

    in the interval (pi/2,pi) the function is f(x)=+cosx so its derivative is sinx and at 3pi/4 its value is 1/rt(2). Observe that i had to find the sign of the function in the neighbourhood of the given point.

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

    f(x)=-cos x in the intervl pi/2 to pi

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

    yes... so the value is positive.

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

    i mean when u plug pi/2 in f(x), f(x) comes positive

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

    f(x)=-cosx in pi/2 to pi derivative of cosx is -sinx so f'(x)=sinx

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

    ok..got it

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

    bingo

  14. 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.