Got Homework?
Connect with other students for help. It's a free community.
Here's the question you clicked on:
 0 viewing
lilly21
Group Title
locate the absolute extrema of the function (if any exist) over the interval. f(x)=2x3 [0, 2]
 2 years ago
 2 years ago
lilly21 Group Title
locate the absolute extrema of the function (if any exist) over the interval. f(x)=2x3 [0, 2]
 2 years ago
 2 years ago

This Question is Closed

infoshark Group TitleBest ResponseYou've already chosen the best response.0
Familiar with the derivative ? can you take the derivative of f(x), if so, what do you get ?
 2 years ago

infoshark Group TitleBest ResponseYou've already chosen the best response.0
what are the roots of 2 ? where does it cross the x axis
 2 years ago

infoshark Group TitleBest ResponseYou've already chosen the best response.0
can y ever be zero if it always equals 2 ?
 2 years ago

infoshark Group TitleBest ResponseYou've already chosen the best response.0
any max extrema then ?
 2 years ago

lilly21 Group TitleBest ResponseYou've already chosen the best response.1
im kinda of confused by ur question :[
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
u got x=2 put it in f(x) to find the extrema
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
thats correct :)
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
wait. for extrema, u take derivative and equate it to 0 means you do, f'(x)=0 but you got f'(x) = 2 hence there is no extrema.....
 2 years ago

lilly21 Group TitleBest ResponseYou've already chosen the best response.1
but you c in my book it has an answer or answers of min (0,3) and max (2,1)
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
i know, there is no global extrema, and so, here we find local extrema by substituting the endpoints. so put x=0 and x=2 and find f(x)
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
*local = absolute
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
whenever we don't get global extrema, we put endpoints....remember this.
 2 years ago

lilly21 Group TitleBest ResponseYou've already chosen the best response.1
i am utterly confused :[
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
lets start over ?
 2 years ago

lilly21 Group TitleBest ResponseYou've already chosen the best response.1
yes please :]
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
ok, absolute extrema means max or min points in the given interval.
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
now to find min or max values, you take derivative of function and set it =0
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
then you get values of x for which the function is min/max. if f'(x) cannot be equal to 0, then there is no global extrema ok ?
 2 years ago

lilly21 Group TitleBest ResponseYou've already chosen the best response.1
or if its like 1/0 right?
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
in that case, we can find 'local' or 'absolute' values at the endpoints, they become min/max values.
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
i can't think of an example when u get 1/0 after taking the derivative.
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
here , you get f'(x) =2 we cannot equate this to 0
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
because 2 can never =0 hence there is no extrema, or as we say, no global extrema
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
but we can find absolute extrema, that is min/max in GIVEN INTERVAL
 2 years ago

lilly21 Group TitleBest ResponseYou've already chosen the best response.1
how do we find these?
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
one of the endpoint is x=2 there what is f(x) = ?
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
so the point is (2,1) and this is one of the extrema we don't know yet whether this is max or min
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
now put other end point, x=0 what is f(x)
 2 years ago

lilly21 Group TitleBest ResponseYou've already chosen the best response.1
wait where did we get x=0?
 2 years ago

jaersyn Group TitleBest ResponseYou've already chosen the best response.0
your interval [0,2]
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
thats where i got x=2 also earlier
 2 years ago

lilly21 Group TitleBest ResponseYou've already chosen the best response.1
ooooooooo okay there will be 3 extrema right???
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
how come 3 ? one for x=2, and one for x=0
 2 years ago

lilly21 Group TitleBest ResponseYou've already chosen the best response.1
o yeah my bad _ :]
 2 years ago

lilly21 Group TitleBest ResponseYou've already chosen the best response.1
we do the same for 0 right ???? plug it into the orig equation? right?
 2 years ago

jaersyn Group TitleBest ResponseYou've already chosen the best response.0
you could just say there's no global min/max since the function is linear right?..
 2 years ago

jaersyn Group TitleBest ResponseYou've already chosen the best response.0
k, thanks. double checking.
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
now put other end point, x=0 what is f(x)
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
so the other point is ?
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
and which one should be min and which one should be max ?
 2 years ago

lilly21 Group TitleBest ResponseYou've already chosen the best response.1
0,3 is min the other is max?
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
yes, thats correct. clear with every step ?
 2 years ago

lilly21 Group TitleBest ResponseYou've already chosen the best response.1
yes sir or mam! :]
 2 years ago

lilly21 Group TitleBest ResponseYou've already chosen the best response.1
thanks so much!
 2 years ago

hartnn Group TitleBest ResponseYou've already chosen the best response.1
your welcome ^_^
 2 years ago
See more questions >>>
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.