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Re: A more computer-related math problem

3-Dec-13 4:47

There is a simple way of course, I wouldn't ask you guys to try 2⁶⁴ combinations Smile | :)

Ok I might, but I didn't.
Here's a start: consider the 1-bit case. 3 out of 4 inputs give 0.
There are several different ways to go from there.

harold aptroot3-Dec-13 5:13

3-Dec-13 5:13

You could also "cheat" and use algorithms and data structures instead of just math, for example: made an ROBDD representing the function "x & y == 0" (that BDD is pretty small) and count its solutions (in time depending mainly on the size of the BDD, not the magnitude of the answer). (that's what my site[^] does)
That way you might not see that it's 3³² though, just the raw number, and it's a little hard to take 1853020188851841 and figure out where it came from, so to speak.

Solve for X

Dalek Dave3-Dec-13 3:43

Dalek Dave

3-Dec-13 3:43

Time yourself.

I reckon under 30 seconds for most people here:

Solve for x:
(x+1)(x+2)(x+6) = x^3+9x^2+4(7x-1)

---------------------------------
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Nagy Vilmos3-Dec-13 3:46

Nagy Vilmos

3-Dec-13 3:46

x=4

speramus in juniperus

ZurdoDev3-Dec-13 3:46

ZurdoDev

3-Dec-13 3:46

x=42

There are only 10 types of people in the world, those who understand binary and those who don't.

Argonia3-Dec-13 3:48

Argonia

3-Dec-13 3:48

x = beer

Microsoft ... the only place where VARIANT_TRUE != true

Corporal Agarn3-Dec-13 4:20

Corporal Agarn

3-Dec-13 4:20

You are only half right:

x = beer + bacon

harold aptroot3-Dec-13 3:49

3-Dec-13 3:49

(x+1)(x+2)(x+6) =
x^3+9x^2+20x+12 = x^3+9x^2+4(7x-1)
20x+12=4(7x-1)
5x+3=7x-1
4=2x
x = 2

Rob Philpott3-Dec-13 3:53

Rob Philpott

3-Dec-13 3:53

Congratulations! I'm sure you get an A in GSCE maths for that, or possibly even an A at A-level these days.

Not that they've dumbed down or anything...

Regards,
Rob Philpott.

Nagy Vilmos3-Dec-13 3:53

Nagy Vilmos

3-Dec-13 3:53

I lost an x somewhere doing it in my befuddled brain.

speramus in juniperus

Roger Wright3-Dec-13 3:51

Roger Wright

3-Dec-13 3:51

x=2

(3)(4)(8) = 8 + 36 + 52
96 = 96

Will Rogers never met me.

David Goebet3-Dec-13 3:56

David Goebet

3-Dec-13 3:56

(x+1)(x+2)(x+6) = x^3+9x^2+4(7x-1)

x³ + 9x² + 20x + 12 = x³ + 9x² + 28x - 4 |-x³

9x² + 20x + 12 = 9x² + 28x -4 |-9x²

20x + 12 = 28x -4 |-20x |+4

16 = 8x

x = 2

if not i would say 42 too $Shucks | :-\$

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Mohamad M. Mohamad3-Dec-13 4:06

Mohamad M. Mohamad

3-Dec-13 4:06

X = 2

My Name in English[^] Translation done By OriginalGriff

R. Giskard Reventlov3-Dec-13 5:38

R. Giskard Reventlov

3-Dec-13 5:38

What's the point?

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me, in pictures

Jörgen Andersson3-Dec-13 5:52

Jörgen Andersson

3-Dec-13 5:52

About eight seconds:
http://www.wolframalpha.com/input/?i=%28x%2B1%29%28x%2B2%29%28x%2B6%29+%3D+x%5E3%2B9x%5E2%2B4%287x-1%29[^]

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ledtech33-Dec-13 6:17

ledtech3

3-Dec-13 6:17

I like this answer Smile | :)

I still don't understand how they got it though

ledtech33-Dec-13 6:16

ledtech3

3-Dec-13 6:16

Ok now my head does hurt.
What kind of math is this ?

Weather forcaster math

Dan Neely3-Dec-13 3:26

Dan Neely

3-Dec-13 3:26

Looking at my forecast for later this week I see no snow on Thursday[^] or Saturday[^], 1-2" of snow during the day on Friday[^] with an additional 1-3" Friday night with a storm total of 3-6".

There's nothing wrong with the minimum total snowfall being listed as 3" since that can be explained by timing uncertainty in when it hits; but if the most I can get during the day is 2" with 3" overnight how can the storm total reach 6"?

Did you ever see history portrayed as an old man with a wise brow and pulseless heart, waging all things in the balance of reason?
Is not rather the genius of history like an eternal, imploring maiden, full of fire, with a burning heart and flaming soul, humanly warm and humanly beautiful?
--Zachris Topelius

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harold aptroot3-Dec-13 3:31

3-Dec-13 3:31

All those numbers are rounded, maybe the raw prediction was 1-2.4" and 1-3.4" (or something sufficiently close).

Nagy Vilmos3-Dec-13 3:39

Nagy Vilmos

3-Dec-13 3:39

It's all those fractals they use in weather predicting, one butterfly can make 1+1=3.

speramus in juniperus

Dan Neely3-Dec-13 3:48

Dan Neely

3-Dec-13 3:48

You really are a special snowflake.

Marco Bertschi3-Dec-13 3:58

Marco Bertschi

3-Dec-13 3:58

He's in fact a really big hailstone.

Veni, vidi, caecus

Dave Kreskowiak3-Dec-13 4:41

Dave Kreskowiak

3-Dec-13 4:41

Hey, 1 + 1 does equal 3, for very large values of 1!

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Shameel3-Dec-13 4:18

Shameel

3-Dec-13 4:18

Better forecast[^]