A community for students.
Here's the question you clicked on:
 0 viewing
mathcalculus
 2 years ago
help with optimization! (attached)
mathcalculus
 2 years ago
help with optimization! (attached)

This Question is Closed

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0okay i understand everything..... except how to find the minimum!

completeidiot
 2 years ago
Best ResponseYou've already chosen the best response.2are you familiar with derivative?

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0i know they got the equation. y=6x+(21000/x)

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0then after i'm not sure how they got: Minimum occurs at 59.16 ft for the length (found on a graphing calc) width: 10500/59.16 = 177.5 ft Perimeter = 710 ft

completeidiot
 2 years ago
Best ResponseYou've already chosen the best response.2ok, well the method they got the minimum is just by using a graphing calculator with a max min function on it doing it manually would involve finding the first derivative of the equation and then setting it equal to zero and then solving for L

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0is there a way to do that without it?

completeidiot
 2 years ago
Best ResponseYou've already chosen the best response.2without the graphing calculator? or without having to do it manually?

completeidiot
 2 years ago
Best ResponseYou've already chosen the best response.2by hand would involve finding the first derivative of the equation and then setting it equal to zero and then solving for L

completeidiot
 2 years ago
Best ResponseYou've already chosen the best response.2because the slope at the minimum point is zero

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0im doing it wrong, even on calculator :/ I'm not getting it.

completeidiot
 2 years ago
Best ResponseYou've already chosen the best response.2\[y = \frac{21000}{x} + 6x\] \[y' = \frac{21000}{x^2} +6\] \[y' =0\] \[0=\frac{21000}{x^2} +6\] solve for x hopefully i didnt screw up the derivative

completeidiot
 2 years ago
Best ResponseYou've already chosen the best response.2\[\frac{1}{x} = x^{1}\]

Psymon
 2 years ago
Best ResponseYou've already chosen the best response.0@completeidiot derivative is fine :3

completeidiot
 2 years ago
Best ResponseYou've already chosen the best response.2im just pointing out the identity that allows you to use the "power" rule for derivatives

completeidiot
 2 years ago
Best ResponseYou've already chosen the best response.2\[y= x^n\] \[y' = nx^{n1}\]

mathcalculus
 2 years ago
Best ResponseYou've already chosen the best response.0im not getting that. i got up to here: y=621000/x^2 then set it to 0

completeidiot
 2 years ago
Best ResponseYou've already chosen the best response.21/x is not part of the problem you can ignore it if you want its just that the identity is sometimes not obvious to other people

completeidiot
 2 years ago
Best ResponseYou've already chosen the best response.2once you set it equal to zero 0=621000/x^2 just solve for x

completeidiot
 2 years ago
Best ResponseYou've already chosen the best response.26= 21000/x^2 x^2= 21000/6 x = sqrt {21000/6}

completeidiot
 2 years ago
Best ResponseYou've already chosen the best response.2any other questions? sorry for any confusion i may have caused
Ask your own question
Sign UpFind 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
 Engagement 19 Mad Hatter
 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.