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steel11
Group Title
Where is this function concave up and concave down.
x^2/(x5)^2
 2 years ago
 2 years ago
steel11 Group Title
Where is this function concave up and concave down. x^2/(x5)^2
 2 years ago
 2 years ago

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klimenkov Group TitleBest ResponseYou've already chosen the best response.1
\[\frac{x^2}{(x5)^2}\]Can you take derivatives?
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
yes. I know i have to take the second derivative, but i having trouble finding out where the 2nd derivative equals zero.
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
I even put the function into a graphing calculator. i still cant get the right answer.
 2 years ago

klimenkov Group TitleBest ResponseYou've already chosen the best response.1
Can you type here what you've got?
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
going to take me a while to get it, have to do chain rule and everything. '_' you can just post the answer if you want. >.> already been on this problem for like an hour
 2 years ago

klimenkov Group TitleBest ResponseYou've already chosen the best response.1
Ok. I will type an answer for you.
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
this was a multiple part question, this is what i have so far. http://gyazo.com/003eb77ccf9977811aa71cf7f65fb35f
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
all those answers are right. just need 7 and 8
 2 years ago

klimenkov Group TitleBest ResponseYou've already chosen the best response.1
\(f''(x)=\frac2{(5 + x)^2}  \frac{8 x}{(5 + x)^3} + \frac{6 x^2}{(5 + x)^4}\) The horizontal asymtote isn't right.
 2 years ago

klimenkov Group TitleBest ResponseYou've already chosen the best response.1
Oh. Sorry. I must check it again!
 2 years ago

klimenkov Group TitleBest ResponseYou've already chosen the best response.1
Sorry, I'm not very good in English. Am I right?dw:1351890529218:dw
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
left is concave downward, right is concave up. so you have it backwards
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
dw:1351890663750:dw
 2 years ago

klimenkov Group TitleBest ResponseYou've already chosen the best response.1
Ok. So when \(x\in(\infty,\frac52)\) it is concave downward. \(x\in(\frac52,5)\bigcup(5,+\infty)\) it is concave upward.
 2 years ago

klimenkov Group TitleBest ResponseYou've already chosen the best response.1
I can solve it right here if you want. It will be not so long.
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
your right. no need to go any further. :P
 2 years ago

klimenkov Group TitleBest ResponseYou've already chosen the best response.1
All you have to do is to solve this:\[\frac2{(5 + x)^2}  \frac{8 x}{(5 + x)^3} + \frac{6 x^2}{(5 + x)^4}=0\]
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
ye, i was having a tough time with that. :l
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
hmm. while your here. could you answer 1 small part to another question? pretty straight forward this time
 2 years ago

klimenkov Group TitleBest ResponseYou've already chosen the best response.1
Ok, ask anything you like.
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
http://gyazo.com/3d89eca12903c12ca28e608233e9f102 find critical points
 2 years ago

klimenkov Group TitleBest ResponseYou've already chosen the best response.1
Hate this congratulations :)
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
people told me there are not critical points to that function, but im not entirely sure if their correct.
 2 years ago

klimenkov Group TitleBest ResponseYou've already chosen the best response.1
The definition of the critical point says that it is that point where the derivative of the function is equal to zero or DOES NOT EXIST. It is your case. Wat are the point where it doesn't exist?
 2 years ago

klimenkov Group TitleBest ResponseYou've already chosen the best response.1
Yes, they are critical.
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
but my site says 3, 3 and 0 are not critical points http://gyazo.com/77d0af7eb8d1e3ce273ff32c24eb58ca
 2 years ago

klimenkov Group TitleBest ResponseYou've already chosen the best response.1
Are you sure that 0 is a critical point?
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
your right, its not. f'(0) does not equal 0
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
but it wont even accept 3 or 3
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
ugh. wait. i think f'(0)= 0. so it must be a critical point
 2 years ago

klimenkov Group TitleBest ResponseYou've already chosen the best response.1
No. It is not right. The derivative is:\[\frac{4 ( x^2+9 )}{( x^29 )^2}\]
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
oh. so what do you do from there. set it equal to zero and solve? that would be 3 and 3 right?
 2 years ago

klimenkov Group TitleBest ResponseYou've already chosen the best response.1
In points 3 and 3 it doesn't exist, so both of them are critical.
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
ok so that is the answer?
 2 years ago

klimenkov Group TitleBest ResponseYou've already chosen the best response.1
Yes. What is the definition of the critical point on your site?
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
http://gyazo.com/a531cae84cdcc8b853ca750f1e2b5e0c
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
im not entirely sure. '_'
 2 years ago

klimenkov Group TitleBest ResponseYou've already chosen the best response.1
Try to type 3,3 insted of 3,3
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
http://gyazo.com/0354e3dc53f2b3172ff9cbbfd156f2a1
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
this is the problem im having. it wont accept anything.
 2 years ago

klimenkov Group TitleBest ResponseYou've already chosen the best response.1
Hm..did you type None into this field?
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
omg. that actually worked
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
yes. Thanks a lot for the help =]
 2 years ago

steel11 Group TitleBest ResponseYou've already chosen the best response.0
i did a combined total of 180 tries on both of the question i asked you. finally got the right answers.
 2 years ago

klimenkov Group TitleBest ResponseYou've already chosen the best response.1
It is strange. Ask your teacher the definition of the critical point. Hope you will solve different problems easily in the future. Good luck for you. I wish you a lot of well. Hope you understand.
 2 years ago
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