A community for students.
Here's the question you clicked on:
 0 viewing
yashar806
 2 years ago
I need help, please
yashar806
 2 years ago
I need help, please

This Question is Closed

yashar806
 2 years ago
Best ResponseYou've already chosen the best response.0I have attached the question

yashar806
 2 years ago
Best ResponseYou've already chosen the best response.0yes, could you explain it ?

satellite73
 2 years ago
Best ResponseYou've already chosen the best response.1ok first off z is 4, so lets forget z and replace it by 4

satellite73
 2 years ago
Best ResponseYou've already chosen the best response.1the volume of the first tube, the one with side \(x\) is \(4\times (\frac{1}{4}x)^2\)

satellite73
 2 years ago
Best ResponseYou've already chosen the best response.1because your entire length is \(x\) and you are folding it in to a square so the side of the square is \(\frac{1}{4}x\)

satellite73
 2 years ago
Best ResponseYou've already chosen the best response.1and therefore the area of the square is \((\frac{1}{4}x)^2=\frac{x^2}{16}\) and since \(z=4\) the volume is \(4\times \frac{x^2}{16}=\frac{x^2}{4}\)

satellite73
 2 years ago
Best ResponseYou've already chosen the best response.1the volume of the second one is easy, since \(z=4\) it is just \(y\)

yashar806
 2 years ago
Best ResponseYou've already chosen the best response.0then we add them togther?

satellite73
 2 years ago
Best ResponseYou've already chosen the best response.1now we use the fact that \(x+y=8\) and so \(y=8x\)

satellite73
 2 years ago
Best ResponseYou've already chosen the best response.1now we add them together, because now we have an expression for the volume in one variable it will be \[V(x)=\frac{x^2}{4}+8x\]

satellite73
 2 years ago
Best ResponseYou've already chosen the best response.1now if this is a calculus question you can take the derivative, set it equal to zero and solve if not, you can say the vertex is at \(\frac{b}{2a}\) with \(a=\frac{1}{4}\) and \(b=1\)

satellite73
 2 years ago
Best ResponseYou've already chosen the best response.1ok good this has a min at the vertex, and i guess a max at the end point of the interval, so be careful about what that is

satellite73
 2 years ago
Best ResponseYou've already chosen the best response.1i guess it is \([0,8]\) since \(x\) must be in there somewhere

yashar806
 2 years ago
Best ResponseYou've already chosen the best response.0Hi just quick question, why we need interval there? how did you know that there should be an inteval?
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.