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anonymous
 one year ago
Cubic help
anonymous
 one year ago
Cubic help

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anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Graph doesn't look very cubic to me though which makes me thing I did it wrong.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0what's the exact question?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0as in what is the exact wording of the question you're trying to answer. positive rate of change → function is increasing negative rate of change → function is decreasing

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2Is it possible to post an image of the original question? That's the fastest way to get help!

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0You're giving a lot of information, but there's no context

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0So I can do cubic regression or do l*w*h where (12x) represents the sides and (x) represents the height of the boxes... whichever one you guys are able to help me with.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Kinda wanted to know how to do it by hand, but maybe that isn't good to know as a prealgebra student.

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2Hints: "where (12x) represents the sides and (x) represents the height of the box)" means: So if the height (x)=1, then the sides are (121)=11, or 1*11*11, V=121 If height is 2, sides are 122=10, volume = 2*10*10=200 in general, if the height equals x, the volume is x(12x)(12x), which is evidently a cubic. Do you agree with the above calculations?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Yeah that makes sense.

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2Yes, a cubic is a polynomial, which is any expression in the form of "the sum of positive integer powers of a variable, each multiplied by a constant".

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2I do not know how you got y=12x^2 + 49.6x + 67.2 but the volume itself is already a cubic (third degree polynomial), and will not need to have a cubic regression, because it is exactly a cubic polynomial.

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2But your table does not correspond to the given constraints of x=height, (12x)=sides, so it cannot be used to "generate" your regression cubic.

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2But your table does not correspond to the given constraints of x=height, (12x)=sides, so it cannot be used to "generate" your regression cubic that represent the results of the problem.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0But if it's wrong then I will just go with the way you showed me.

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2In your table, I do not understand what you meant by "size of corner cut ". I use x=height, as per instructions.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0size of corner cut meants (remember I used grid paper to make cubes) I had to cut off one square on each corner. Let me draw it for you okay. I'm really sorry for confusing you. I did a very bad job explaining everything.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Give me a few minutes. please.

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2So that means the height. dw:1440381788262:dw

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0right but in the first drawing it's 10 by 10

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2So you need to make a table: dw:1440381900195:dw

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2Can you please look at my table and see if you agree with it?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0for that table you draw for 3 would be 123 = 9 3*9*9 or 243

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Yeah that makes sense to me.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0So was my equation wrong then? I can't get an equation from your table you drew right?

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2So use this new table and try to fit a cubic and see what you get. "Our" volume is x(x2)^2=x^324x^2+144x. Your "regression" cubic should give exactly the same expression.

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2Remember to fit a cubic you need at least 4 points, and preferably more if you're doing regression.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0wait what do I put in for x?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Are you there @mathmate

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2Sorry, I was afk. a bunch of numbers, like 1,2,3,4,5,6, or 2,4,6,8,10, ... If everything is calculated correctly, they should all give the same cubic polynomial.

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2The numbers don't have to be evenly spaced like my examples, they could be x=1,2,5,10,21 if you want.

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2Oops, cannot be greater than 12! So forget the 21!

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0I graphed this on my paper I did my y axis by 10's and my x axis 12345 but skipped every two lines

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0not sure if that's relevant

mathmate
 one year ago
Best ResponseYou've already chosen the best response.2Trick to graphing by hand is to get the smallest and largest y to start. So start with the table. dw:1440383506458:dw so make a yscale high enough for 256, and x from 1 to 10.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0okay thanks for your help. Really appreciate you sitting here and going over this with me :)))
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