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Loser66
 one year ago
A total x feet of fencing is to form 3 sides of a level rectangular yard. What is the maximum area of the yard in term of x?
A) x^2/9
B) x^2/8
C) x^2/4
D)x^2
E)2x^2
Please, help
Loser66
 one year ago
A total x feet of fencing is to form 3 sides of a level rectangular yard. What is the maximum area of the yard in term of x? A) x^2/9 B) x^2/8 C) x^2/4 D)x^2 E)2x^2 Please, help

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freckles
 one year ago
Best ResponseYou've already chosen the best response.2oops meant to write x

freckles
 one year ago
Best ResponseYou've already chosen the best response.2\[2L+W=x \\ A=LW=L(x2L)\]

freckles
 one year ago
Best ResponseYou've already chosen the best response.2So we want to find A' here

freckles
 one year ago
Best ResponseYou've already chosen the best response.2x is a constant I believe \[A=Lx2L^2 \\ A'=x4L \\ A'=0 \implies x=4L \\ A=L(x2L)=L(4L2L)=L(2L)=2L^2 \\ \] I think you can find A in terms of x now since x=4L

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0Yes. Thanks a lot. I got the right answer. It is not test, just practice exam with the answer sheet. But I want to know logic.

freckles
 one year ago
Best ResponseYou've already chosen the best response.2Why are you doing calculus 1 problems?

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0oh, is it calculus problem??

freckles
 one year ago
Best ResponseYou've already chosen the best response.2Yes it is an optimization problem

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0Question: why do you link to derivative?

freckles
 one year ago
Best ResponseYou've already chosen the best response.2because it say to maximize

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0I assume it is an algebra problem and get no outlet

freckles
 one year ago
Best ResponseYou've already chosen the best response.2usually those in the cal problems I have seen they actually gave a number instead of saying x

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0I am prepare for my GRE test for maths major students. ha!!!

freckles
 one year ago
Best ResponseYou've already chosen the best response.2http://tutorial.math.lamar.edu/Classes/CalcI/Optimization.aspx this example one here is pretty similar

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0My tough one is English, not math.

freckles
 one year ago
Best ResponseYou've already chosen the best response.2except as I said they say 500 feet instead of x feet

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0Any tips for GRE math practice?? I have only 1. :)

freckles
 one year ago
Best ResponseYou've already chosen the best response.2there was a question and I think it was on the gre it was my favorite question to give me a sec and I will remember it

freckles
 one year ago
Best ResponseYou've already chosen the best response.2solve for x+y \[x^2+y^2+2xy+2x+2y=1 \]

freckles
 one year ago
Best ResponseYou've already chosen the best response.2there was a similar question on the gre or it might have been on another standard test can't remember which standard test

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0hihihi... I have time. I will study carefully before taking the test. But you know, I am old. hahaha..... I am slow!!

freckles
 one year ago
Best ResponseYou've already chosen the best response.2that question isn't too bad did you want me to show you how to do it or did you want to try it first

freckles
 one year ago
Best ResponseYou've already chosen the best response.2\[x^2+2xy+y^2+2x+2y+1=0 \\ (x+y)^2+2(x+y)+1=0 \\ (x+y+1)^2=0 \\ x+y+1=0 \\ x+y=1 \]

freckles
 one year ago
Best ResponseYou've already chosen the best response.2I turned it into a quadratic in terms of (x+y)

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0What if we let x+y =t??

freckles
 one year ago
Best ResponseYou've already chosen the best response.2good luck on your gre if i could figure out anything to tell you to help you I will I probably should have studied for it back in the day more than I did

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0Sure. Again, thanks for the help.

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0What is the units digit in standard decimal expansion of the number 7^(25) I don't get what it mean

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0since \(7^{25} = 1.34106862 *10^{21}\) hence the number of digits after decimal point is 8 but it is not one of the options which are 1,3,5,7 or 9

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0To this problem, if I don't have calculator, how can I find out the answer?

freckles
 one year ago
Best ResponseYou've already chosen the best response.2so you are trying to find out the length of the number 7^(25) ?

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0problem 14 https://www.ets.org/s/gre/pdf/practice_book_math.pdf

freckles
 one year ago
Best ResponseYou've already chosen the best response.2the units digit is the ones digit

freckles
 one year ago
Best ResponseYou've already chosen the best response.2wait standard notation is not scientific notation is it ?

freckles
 one year ago
Best ResponseYou've already chosen the best response.2there was need to write in scientific notation because standard notation is different from scientific notation

freckles
 one year ago
Best ResponseYou've already chosen the best response.27^(25) mod 10 will give you number in 1's digit

freckles
 one year ago
Best ResponseYou've already chosen the best response.2\[4^2=16 \text{; 16 is standard notation for } 4^2 \\ 4^2=1.6 \times 10 \text{ is sceinfict notation }\]

freckles
 one year ago
Best ResponseYou've already chosen the best response.2I missed the word no in there was need to write in scientific notation there was no need to write in scientific notation*

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0to this http://mathcentral.uregina.ca/QQ/database/QQ.09.06/tyrone1.html they said that the units digit is the last digit of the number in standard form in decimal form, the unit digit of 7^25 is the last one, which is 2, not 7 : (

freckles
 one year ago
Best ResponseYou've already chosen the best response.2\[7^{2} \mod 10=9 \\ 7^4 \mod 10 =9 \cdot 9 \mod 10=81 \mod 10=1 \\ 7^{4(6)+1} \mod 10=(7^4)^6(7) \mod 10=1^6(7) \mod 10 =7 \\ 7^{25} \mod 10=7 \]

freckles
 one year ago
Best ResponseYou've already chosen the best response.2the units digit is the first number it is the one's digit that is what that picture above says also

freckles
 one year ago
Best ResponseYou've already chosen the best response.2for example 61 do you call 1 the first digit because I do and 6 is the last digit 1 is in the one's place (or the units place) 6 is in the ten's palce

freckles
 one year ago
Best ResponseYou've already chosen the best response.2oh I think I see where you are getting confused

freckles
 one year ago
Best ResponseYou've already chosen the best response.2\[7^{25} = 1.34106862 *10^{21} \] you think this equality is exact when it is not

freckles
 one year ago
Best ResponseYou've already chosen the best response.2and even if it was exact you would say the units digit is 0 but it is not the case because this equation is not exact

freckles
 one year ago
Best ResponseYou've already chosen the best response.2like you still need to move that decimal to the right like 21 times

freckles
 one year ago
Best ResponseYou've already chosen the best response.22 is not in the one's digit

freckles
 one year ago
Best ResponseYou've already chosen the best response.2the number where it says result is the number in standard notation

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0oooooooooooooooooh!! got you

freckles
 one year ago
Best ResponseYou've already chosen the best response.2a mod 10 should always give you the units digit of a

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0modular method help me out 7^0 1 last digit 7^1 7 last digit 7^2 9 7^3 3 7^41 hence the cycle is 4, 25 = 4*6 +1, hence \(7^25 = 7^24 *7 , but the last digit of 7^24 is 1 then *7 =7

Loser66
 one year ago
Best ResponseYou've already chosen the best response.0Thanks a ton. :) I do appreciate.

freckles
 one year ago
Best ResponseYou've already chosen the best response.2interesting practice exam I think they have made changes to it seen I last took the gre I feel like that was 8 years ago or something :p

freckles
 one year ago
Best ResponseYou've already chosen the best response.2I don't remember linear algebra or number theory on it

freckles
 one year ago
Best ResponseYou've already chosen the best response.2but maybe there was some
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