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#3201 Re: Exercises » Is this cool with you? » 2010-04-25 00:43:36
Hi Bobby,
I had already done something similar to yours:
#3202 Re: Exercises » Is this cool with you? » 2010-04-24 14:14:48
Hi Bobby,
#3203 Re: Exercises » Is this cool with you? » 2010-04-24 03:31:50
Hi Bobby,
#3204 Re: Exercises » Is this cool with you? » 2010-04-24 00:07:36
Hi Bobby,
That's a neat trick!
Same answers as mine, and it took 18% less time. 
#3205 Re: Exercises » Is this cool with you? » 2010-04-23 17:22:49
Hi Bobby,
#3206 Re: Exercises » Is this cool with you? » 2010-04-23 12:40:25
Hi Bobby,
#3207 Re: Exercises » Is this cool with you? » 2010-04-22 02:34:58
Hi Bobby,
#3208 Re: Help Me ! » Any puzzles? » 2010-04-21 02:48:53
...at least they Look Good!!
If that's as in content...solving them destroyed quite a few hours that could otherwise have been devoted to productivity.
If that's as in appearance...thanx! All done in MS Word for clarity.
i'll notify after getting any answers!
Just post 'em in their threads. Some of them will take several hours (I think), so I may not hear from you about them for a bit.
#3209 Re: Maths Is Fun - Suggestions and Comments » College Algebra - Volunteers Wanted » 2010-04-20 02:48:03
* Others say int(-3.65) = -3 (which is the integer closest to zero)
I reckon this might be better:
* Others say int(-3.65) = -3 (the same as the Ceiling function)
It mirrors the bracketed comment for the -4 case, giving better consistency.
Furthermore, for negative numbers, -1 "is the integer closest to zero", not -3.
Some say frac(-3.65) = 0.35
Others say frac(-3.65) = -0.65
I'd prefer this, which I think ties it in more clearly with the part that int plays in this:
Some say frac(-3.65) = 0.35 ...... i.e., -3.65 - (-4)
Others say frac(-3.65) = -0.65 ...... i.e., -3.65 - (-3)
#3210 Re: Maths Is Fun - Suggestions and Comments » College Algebra - Volunteers Wanted » 2010-04-19 02:50:26
Hi MathsIsFun,
The comment that you added:
HOWEVER: many calculators and computer programs actually give the answer:
frac(-3.65) = -0.65
Because they use frac(x) = x - int(x) instead.
What I said in my other post:
Excel, OOoCalc and my Sharp PC-1500A BASIC pocket computer say:
-3.65-INT(-3.65) = 0.35Two other software calculators (BCalc and Microsoft Calculator for XP) say:
-3.65-INT(-3.65) = -0.65
In the first example, INT(-3.65) = -4, while in the second INT(-3.65) = -3.
I think it is the way that INT handles negative decimal numbers in different calculators etc that gives the differing results, not necessarily that they use frac(x) = x - int(x).
#3211 Re: Help Me ! » Any puzzles? » 2010-04-19 02:17:51
Hi ZHero,
Some of my puzzles - my favourites - haven't hit it off at all here on MIF; but you never know...
You may like these four logic puzzles that I posted some months back. No one here has admitted to solving them yet:
1. Callous Count Crewell - a great, fun, storyline cross-number puzzle, something like Little Pigley Farm (see below).
2. NOHOW - quite a difficult cross-number puzzle from 1966 by Rhombus, whose tough brain teasers have been widely published.
3. Joan's telephone number & my YOB. This is a puzzle in 2 parts. Part 1, which was published in a puzzle magazine, was composed by a good friend of mine. I composed Part 2, which consists of some interesting (I hope) nonsense, and a tricky bit for which I think you'll want to use a computer to help you solve it.
4. The missing dollar (& the 2 extra dollars) - easy.
The next three have been solved, but I recommend you try them too:
A. Little Pigley Farm - one of the best storyline cross-number puzzles I've seen.
B. More or Less - an easy(ish), well-constructed cross-number puzzle.
C. Self-Referential Aptitude Test - one of the most enjoyable puzzles I've ever done. A terrific brain-teaser!
Hope you like them!
#3212 Re: Maths Is Fun - Suggestions and Comments » College Algebra - Volunteers Wanted » 2010-04-18 10:52:59
Re frac(x) where x = -3.65:
I tested this on my two scientific calculators that have the frac function...an HP 48SX and a Canon F-802P.
Both say this:
frac(x) = -.65
int(x) = -3
int(x) + frac(x) = -3.65
My first inclination, which no doubt stems from my use of these calculators, is that both the frac and int functions should simply select their particular side of the decimal point and maintain the sign. I don't know what is generally thought or taught, but to me it seems the intuitive approach.
Excel, OOoCalc and my Sharp PC-1500A BASIC pocket computer say:
-3.65-INT(-3.65) = 0.35
Two other software calculators (BCalc and Microsoft Calculator for XP) say:
-3.65-INT(-3.65) = -0.65
#3213 Re: Exercises » What do you think? » 2010-04-18 05:00:26
Hi Bobby,
The alphametic .
#3214 Re: Exercises » What do you think? » 2010-04-17 22:19:59
Hi Bobby,
to Champernowne's number.
#3215 Re: Exercises » What do you think? » 2010-04-12 02:24:37
Hi Bobby,
Does anyone still know who BB is?
I can't admit to 'still' knowing anything about that (not that I ever really did), because Tigeree says I'm 27.
I'll bore you with the last instalments of the massive missives about Dilbert's Salary Theorem's proofs etc. Here they are, in order from left to right.
Don't bother with them until you have absolutely nothing better to do!
#3216 Re: Exercises » What do you think? » 2010-04-12 00:38:34
Yes...I wrote the disproof. 'Twas just a bit of fun with a friend of mine, who emailed me the theorem, claiming "Can this theorem be disproved??? I don't think so!!!".
I couldn't resist the challenge!
It went on from there. My disproof was 'Reproved', which I then followed up with 'Unreprooved' (the last of them).
#3217 Re: Exercises » What do you think? » 2010-04-12 00:28:20
It actually makes sense to me.
Likewise. It makes perfect ¢¢ to me too.
Mine was just a totally-tongue-in-cheek disproof of a well-established, real-life factual theorem.
#3218 Re: Exercises » What do you think? » 2010-04-11 23:35:20
Hi Bobby,
My answer assumes that there isn't a work-capacity imbalance in the workers of the two groups: such as, for example, that which is in 'Dilbert's Salary Theorem' and my disproof to it (see image).
EDIT: Ignore the second image. I replaced it with the first one, but that second one won't delete.
#3219 Re: Exercises » Is this cool with you? » 2010-04-09 02:40:00
Hi Bobby,
#3220 Re: Exercises » What do you think? » 2010-04-08 21:34:35
Hi Bobby,
I entered "Solve x^3 + 1/x^3 = 52 for x" into W|A, and its interpreter got my drift. That's an excellent feature for novices like me!
It gave out the formula you posted, so if I'd used W|A instead of Excel I might have avoided that inaccuracy problem.
I didn't use this idea because I found one that gives a general solution for any power.
Mine does too (I think), now that I've got rid of that approximation.
Thanks for your well-wishes, but I had a rotten day at work. Someone muffed it, which wrecked my plans...and so I got next-to-nothing done. 
I should have stayed home and enjoyed myself on MIF...which also gets next-to-nothing done.
#3221 Re: Exercises » What do you think? » 2010-04-08 12:32:46
Did you try W.A.
No I didn't. I only 'know' the tiniest bit of Mathematica...which only came about because of some correspondence I had with the person who solved my YOB puzzle by using Mathematica. I dabbled with M. a bit initially but thought it was too complex a program for a mere dabbler like me.
I put your formula into W.A. and had a quick look at the results. Have to go to work now, so a better look will have to wait until tonight.
#3222 Re: Exercises » What do you think? » 2010-04-08 12:02:34
Hi Bobby,
...what techniques did you use to find your 3.73.... answer.
Nothing that involved much thinking or structure....Excel's Solver, set to high precision. I couldn't come up with a logical technique.
#3223 Re: Exercises » What do you think? » 2010-04-08 03:15:47
Hi Bobby,
That's a pretty big hint...nearly as big as the 'great big hint' that I gave to my NOHOW puzzle.
It works perfectly for all cases that I tried it on, but I've got no idea at all about the reasoning behind it (I tried). What are the steps for arriving at that formula?
I tested my improved general formula by using my calculator and WolframAlpha on various powers up to 636 - which is the highest W.A. will go to - and they agree on all.
But there are further improvements too? I'll need another hint!
#3224 Re: Exercises » What do you think? » 2010-04-07 13:58:37
And Tigeree the coolest dudess in Australia.
#3225 Re: Exercises » What do you think? » 2010-04-07 13:53:07
Hi Bobby,
What do you get for your equation when y = 25?
And for other higher powers: inaccuracy.
I thought that might happen because of the approximation, and should have checked it out in WolframAlpha or my high-precision calculator first as they would have told me that in a flash...but I didn't think of it (rushing).
I had another idea in mind but didn't finish it. This one seemed to work - at least it did for the low powers - and so I posted it.