A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing


  • 3 years ago

From problem set 4 unit 2C problem 10 I have some problems understanding the solution. The goal is to find the route that requires the minimum time to travel between to points. The equation to optimize is T=[(x^2+100^2)^1/2]/5+[((a-x)^2+100^2)^1/2]/2 .I differentiate obtaining the same result as the solution which is t prime equals to: [x/5(100^2+x^2)^1/2]+[a-x/2((a-x)^2+100^2)^1/2]. At this point the solution substitutes both terms with sin, but both numerators are adjacent side to the angles not opposite.. Could someone please help me understand better this problem? Thank you in advance

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

    We get this question here about once a week, because the problem and solution given in the materials are erroneous. The most important errors in the problem was labeling the wrong angles alpha and beta, which should instead be angles made with a line perpendicular to the shore rather than angles made with the shore. The error switches the result to cosine because the sine of an angle equals the cosine of its complement. Here's a corrected version of the problem and solution: http://assets.openstudy.com/updates/attachments/522ad142e4b0a8663d5580c8-creeksider-1378561866464-2c10corrected.pdf

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

    thank you

  3. 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.