4's only

4's only

Posers and Puzzles

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s
Fast and Curious

slatington, pa, usa

Joined
28 Dec 04
Moves
53223
29 Jun 14

Originally posted by Agerg
Well if we're allowed logs then (as per the wikipedia article for this puzzle) we have
-sqrt(4)log(log(sqrt( ... n times ... (sqrt(4) ... ))/log(4))/log(4)
= -2 log(2^(-n)log(4)/log(4))/log(4)
= 2n log(2)/log(4) = 2n * .5 = n 🙂

and so

-sqrt(4)(log(log(sqrt(4))/log(4)))/log(4) = 1
-sqrt(4)(log(log(sqrt(sqrt(4)))/log(4)))/log(4) = 2
-sqrt(4)(log(log(sqrt(sqrt(sqrt(4))))/log(4)))/log(4) = 3
.
.
.
.
Can you imagine what that solution would look like for 1,000,000,000,000🙂

A
The 'edit'or

converging to it

Joined
21 Aug 06
Moves
11479
29 Jun 14
1 edit

Originally posted by sonhouse
How does 0! = 1? I thought factorial for zero would be zero, zero times one should be zero and one times zero should be zero.
How does 0! = 1? I thought factorial for zero would be zero, zero times one should be zero and one times zero should be zero.
It is defined to be 1. A nice explanation of why can be found at:

http://mathforum.org/library/drmath/view/57128.html


Can you imagine what that solution would look like for 1,000,000,000,000🙂
Heh...I'll be honest and say that I cannot imagine what the solution would look like!

Joined
26 Apr 03
Moves
26771
29 Jun 14
5 edits

Hmm, following the pattern and using exactly 4 4's

"-(log(log(" & { "sqrt(" x 10^12} & "4)" & { " )" x 10^12} & "/log(4))/log(4/sqrt(4))"

Where & means concatenate the strings, and { string x n} means repeat string n times, I think that is 7000000000032 characters

according to http://amazingbibletimeline.com/bible_questions/q10_bible_facts_statistics/
there are 3,116,480 letters in a king james bible, so we could print the sum in the equivalent of 2,246,124 bibles. If each book was 4 cm thick, the stack of books would be 90km high.

Factorial n is the number of ways of arranging n different things, so the way I always think about it is that there is 1 way of having absolutely nothing.

f
Defend the Universe

127.0.0.1

Joined
18 Dec 03
Moves
16687
01 Jul 14

Originally posted by AThousandYoung
4^4+4/4

PEMDAS

No Parentheses
Exponenent is next...

256+4/4

Then Multiplication and Division...

256+1

Then Addition and Subtraction...

257

Parentheses are unnecessary to avoid ambiguity. Order of Operations...
Thank you.

Parenthesis do not exist only for entering things into a calculator

0,1,1,2,3,5,8,13,21,

Planet Rain

Joined
04 Mar 04
Moves
2702
06 Aug 14
1 edit

Originally posted by sonhouse
Can you imagine what that solution would look like for 1,000,000,000,000🙂
Aw, that's easy:

(4/.4)^(4!/sqrt(4))

EDIT: I typed .4 as 0.4 originally, so…fixed!

0,1,1,2,3,5,8,13,21,

Planet Rain

Joined
04 Mar 04
Moves
2702
06 Aug 14

Wait a minute, couldn't 1000 more easily be rendered thus:

4(4^4)-4!

Or has this been done already?

G

santa cruz, ca.

Joined
19 Jul 13
Moves
376505
07 Aug 14

Originally posted by Soothfast
Wait a minute, couldn't 1000 more easily be rendered thus:

4(4^4)-4!

Or has this been done already?
simple is more appealing and using the log function can lead to some very ugly solutions
I like your solution

Joined
26 Apr 03
Moves
26771
17 Aug 14

But the log function works mindlessly for any integer, that was the point of it, not to give the most elegant answer for all integers, but to prove an answer exists for *every* integer.

G

santa cruz, ca.

Joined
19 Jul 13
Moves
376505
19 Aug 14

Originally posted by iamatiger
But the log function works mindlessly for any integer, that was the point of it, not to give the most elegant answer for all integers, but to prove an answer exists for *every* integer.
gotcha

tws

Joined
19 Sep 11
Moves
11665
26 Aug 14

I think that I have got a long way towards 100. If anybody is interested I'll go and find my solution . . . . . . TWS

Already mated

Omaha, Nebraska, USA

Joined
04 Jul 06
Moves
1115323
08 Sep 14

Originally posted by lemondrop
11 is open for a solution
For 11, I'll ask the "right-brained"question:

Why not take the already solved 13 and subtract the already solved 2? Trivial, no? Or am I missing something?

Quiz Master

RHP Arms

Joined
09 Jun 07
Moves
48793
08 Sep 14

Originally posted by coquette
For 11, I'll ask the "right-brained"question:

Why not take the already solved 13 and subtract the already solved 2? Trivial, no? Or am I missing something?
You can only use FOUR 4's

Already mated

Omaha, Nebraska, USA

Joined
04 Jul 06
Moves
1115323
12 Sep 14

Originally posted by wolfgang59
You can only use [b]FOUR 4's[/b]
thanks

DC
Student

Aylesbury

Joined
08 Nov 14
Moves
45951
12 Nov 14

11 == 44/(sqrt(4) + sqrt(4))

Joined
26 Apr 03
Moves
26771
14 Nov 14
1 edit

=(4!-sqrt(4))*sqrt(4)/4
=-sqrt(4)(log(log(sqrt(sqrt(sqrt(sqrt(sqrt(sqrt(sqrt(sqrt(sqrt(sqrt(sqrt(4))))))))))))/log(4)))/log(4)