"MATH" Problem

i believe 38, but not positive.

didnt really go over it much, but i think the key lied in 5 ? 2 = 11 and 3 ? 2 = 7. looks like theres a pattern there and i just did 2 ?4 + 6*4 to get 8?4. if you want the answer try to find a pattern using that.

We can just use opetors such as + and x ?

There can be more than one solution if you put the problem this way.
One can be to use some polynomials interpolation for X+Y. The easiest would be Lagrange polynomials.

18 would be my guess if its not a pure math question but instead a abstract logic question because...

(5 ? 2) + (3 ? 2) = (8 ? 4)

or...

11 + 7 = 18

On April 01 2014 05:23 HotChip wrote: 18 would be my guess if its not a pure math question but instead a abstract logic question because... (5 ? 2) + (3 ? 2) = (8 ? 4) or... 11 + 7 = 18

+1
should work for 80% of math cases as well, unless it's something nonlinear like ?= ^ or ! w/e

On April 01 2014 05:23 HotChip wrote: 18 would be my guess if its not a pure math question but instead a abstract logic question because... (5 ? 2) + (3 ? 2) = (8 ? 4) or... 11 + 7 = 18

this should work often, but its likely a bigger number. 4?5 is 30, 2?4 is 14, 8?4 is likely much larger than 14.

for some reason i dont feel like putting much time into this lol, its a bit too much of a guess and check type game to be fun, kinda just want the answer

I happen to have mathcad on this computer so completely against the spirit of the problem I decided to stick a random curve through those 4 points (as if they were in euclidean 3 space), and see where it went through the 5th. I chose ax^2+bx+cy^2+dy=z. This curve goes through (8,4,21.592) to 3d.p.

Solved, bitches.

+ Show Spoiler +

So is the answer 38? Isn't it just 8+9+10+11 = 38 ?

Pattern is x ^ y = z, where

"z is the sum of y natural numbers beginning by x."

5+6=11
2+3+4+5 = 14
3+4 = 7
4+5+6+7+8 = 30

On April 01 2014 12:14 Graisseux wrote: So is the answer 38? Isn't it just 8+9+10+11 = 38 ? Pattern is x ^ y = z, where "z is the sum of y natural numbers beginning by x." 5+6=11 2+3+4+5 = 14 3+4 = 7 4+5+6+7+8 = 30

yup this is it.

Are there not infinite solutions?

Here are three:
z = x*y + 0.5*y^2 - 0.5*y
This would make 8 ? 4 = 38

z = 3.41413196069256*y + 0.22531586335985*y*x^2 - 2.99953205428171 - 0.0327562002807673*x^3
This would make 8 ? 4 = 51.567

z = 0.617846750727388*y + 1.11178467507274*x*y + 0.276430649854522*y^2 - 1.34141610087286 - 0.223569350145477*x
This would make it 39.341

You do realize that you will need an extra term everytime a hint is added, this kind of fit couldn't be more wrong.

On April 01 2014 12:14 Graisseux wrote: So is the answer 38? Isn't it just 8+9+10+11 = 38 ? Pattern is x ^ y = z, where "z is the sum of y natural numbers beginning by x." 5+6=11 2+3+4+5 = 14 3+4 = 7 4+5+6+7+8 = 30

n1

On April 01 2014 12:14 Graisseux wrote: So is the answer 38? Isn't it just 8+9+10+11 = 38 ? Pattern is x ^ y = z, where "z is the sum of y natural numbers beginning by x." 5+6=11 2+3+4+5 = 14 3+4 = 7 4+5+6+7+8 = 30

nice one. So you can put it like
z= [(x+y)*(x+y-1)-x*(x-1)]/2
so also :
z=1/2*(y²+2xy-y) which gives another polynomial than the one from Oly. (but he "forced" a special form)

Obviously there are many answers, but it may be the polynomial with the the lowest powers.
And maybe the only one with only integers as coefficients.

The only answer is this:



Stop with the polynomes, they don't explain or model anything, they just fit the hints. There will always be an infinity of polynomes that fit any set of data and that's why they are bad, it's because they are logicless.

For example, because you can somewhat fit the function y = rounddown(x) by the ugly polynome y = 2E-12x6 - 0.0328x5 + 0.3692x4 - 1.4807x3 + 2.5175x2 - 0.6343x - 0.0224 doesn't mean the polynome is meaningful nor correct:

Your solution is a polynom... and no, there is not one and only one answer. So I won't stop
I took polynoms but there would be plenty of others. Why yours would be better ? It is one, nothing more. Yes you can put it in a simple way and even explain it with some words making it meaningful to your eyes. It does not make the others not solution to the problem.

Again, I understand that my point of view here is purely mathematical and not "logical" or what you call meaningful, and again you found this "nice" solution while I did not.

I had to google polynomials verify this, so from the wiki: "A polynomial [...] can be expressed more concisely by using summation notation"

I guess I stand corrected, thank you

About the problem, I felt like it had the clear context of having been created by a human, expecting a human answer. But then if we take the context out of it I agree, all answers are equal.

EDIT: By the way I realize I didn't look at your answers long enough, I thought they were full of numerical coefficients like in the previous post, which made me dismiss them as ugly hehe my bad.