A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing


  • 5 years ago

Let F be the function given by f(x)= 2xe^x. Determine the interval(s) on which the graph is concave down.

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

    Well, took find where a function concave down you know we take the second derivative and set it equal to zero to find the points of concavity. When this is done you get: 4e^x + 2xe^x = 0 Divide by the constant '2'. e^x(2+x) = 0 And while you're at it, also divide by e^x since this will never be zero. We get: x + 2 = 0 x = -2 So the intervals obtained are: (neg. infinity, -2) & (-2, pos. infinity) Substitute a value from each interval into the 2nd derivative of F, F'' = (x+2): 1. The first interval yields a negative value. 2. The second yields a positive value. So the interval that concave down is the one that yields the negative value: (negative infinity, -2)

  2. 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...


  • 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.