Math Is Fun Forum

  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

#51 Re: Puzzles and Games » Add 13 more and post it forever. » 2010-02-08 04:59:00

624 = 2[sup]4[/sup] + 2[sup]5[/sup] + 2[sup]6[/sup] + 2[sup]9[/sup]

#56 Puzzles and Games » Periodic Table Memorisation Game » 2010-02-06 20:38:26

Devantè
Replies: 13

http://www.sporcle.com/games/elements.php

Useful game to memorise the periodic table. Whether you're memorising them by group, period, or possibly even backwards, that game'll help you.

Unfortunately, I can't find any game that lets you memorise anything else to do with the periodic table - i.e. compound names, or electron shell capacities. Though, I guess you could just do that on paper.

#59 Re: Help Me ! » solving 5 simultaneous equations with matrices » 2010-01-26 03:48:44

It looks like it can easily be solved by normal means. We are given;

ab = 1
bc = 2
cd = 3
de = 4
ea = 6

Multiply the five equations together;

a²b²c²d²e² = 144

=> abcde = 12

=> cde = 12

=> e = 4

Then just substitute back into ea, and then the rest. That looks like the simplest way to do it - I don't see why one would choose any other method, especially with matrices.

#60 Re: Help Me ! » how to simplify this equation? » 2010-01-24 05:17:02

The LHS of the equation reduces to y after noting that the divergence of a curl is zero, and

the

is cancelled by the integral in the denominator using the above form and a change of variables.

The right hand side presumably falls to a similar sort of identity application; I would guess the last two terms are zero and the first two fractions probably almost entirely cancel. Anywho, I'll let the interested figure the rest of it out. This will take a fair bit of time to do.

#61 Re: Help Me ! » math problems » 2010-01-23 09:35:28

Hello -- registered at your site, and testing for bugs.

It's a nice idea... I wish you the greatest success. I'll submit a few problems, and see how it goes.

#64 Re: Dark Discussions at Cafe Infinity » Try this personality test. » 2010-01-22 09:08:33

INTJ

Introverted - 33
Intuitive - 75
Thinking - 50
Judging - 22

You are:

    * moderately expressed introvert
    * distinctively expressed intuitive personality
    * moderately expressed thinking personality
    * slightly expressed judging personality

/wrists

#70 Re: This is Cool » Pi to a Million Decimal Places! » 2010-01-13 19:18:19

I'm at a steady 250-ish... haven't found the time to memorise anymore. At one point I wanted to go for the world record, but it seems a little pointless now, as I'd have to spend several years of my life doing it - which I would prefer not to do.

Good thing to have in your back pocket, though. I've found that it has helped me memorise other things, such as essays - you can hone your technique with pi.

#71 Re: Jai Ganesh's Puzzles » 10 second questions » 2010-01-11 04:21:59

Ganesh, what was your method for calculating the day of the week for any given date?


#73 Re: Jai Ganesh's Puzzles » 10 second questions » 2010-01-09 22:51:35

ganesh wrote:

1955. What day of the week was Fifteenth September, 1969 AD?

Board footer

Powered by FluxBB