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

You are not logged in.

- Topics: Active | Unanswered

Pages: **1**

**RauLiTo****Member**- From: Bahrain
- Registered: 2006-01-11
- Posts: 142

hello everybody ... in fact i dont know how to start

as you all know i am an arabian person ... i decided to make a topic in an arabic forum about math '' enjoy the math '' and i need some questions , tricks , math magic ... to put there so i need your help lovely members !!! who can give me links ? who can put questions not difficult ones but cool and nice question which make you interested in math !!!

thanks again

ImPo$$!BLe = NoTH!nG

Go DowN DeeP iNTo aNyTHinG U WiLL FinD MaTHeMaTiCs ...

Offline

**RauLiTo****Member**- From: Bahrain
- Registered: 2006-01-11
- Posts: 142

views : 16

replies : 0

...

ImPo$$!BLe = NoTH!nG

Go DowN DeeP iNTo aNyTHinG U WiLL FinD MaTHeMaTiCs ...

Offline

**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,684

You could start with Add Two Numbers and the Answer is Always 1089

And then choose from Maths Puzzles and quizzes

And then onto Math and Logic Puzzles

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

Offline

**Zhylliolom****Real Member**- Registered: 2005-09-05
- Posts: 412

You could always use my historical proof that *i[sup]i[/sup]* = *e[sup]-π*/2[/sup] ∈ **R**. I did it for a talent show and won, so I guess it could be used as good mathematical magic. It was a great day for mathematics. If you would like me to write out the problem, just ask.

Offline

**Ricky****Moderator**- Registered: 2005-12-04
- Posts: 3,791

Zhylliolom, I get

, where n is an integer. Could I see your work?Interesting question though, I have to say.

"In the real world, this would be a problem. But in mathematics, we can just define a place where this problem doesn't exist. So we'll go ahead and do that now..."

Offline

**Zhylliolom****Real Member**- Registered: 2005-09-05
- Posts: 412

Hopefully we all know Euler's formula:

For this problem, let 0 ≤ θ ≤ 2π. Now ask yourself, for what value of θ will *e[sup]i*θ[/sup] = *i*? Why yes, it's π/2!

So now we know that *e[sup]i*π/2[/sup] = *i*. Now let's take it to the next level:

Now if we remove the restriction 0 ≤ θ ≤ 2π, then we get the general solution

where *n* ∈ **Z**. I'm not sure why you have just *n* and not 2*n*, Ricky. Odd values of *n* in your solution would give

Now take a simple case of some 0 ≤ θ ≤ 2π that could give *e[sup]i*θ[/sup] = -i. 3π/2 is our value. Then

So, given the same interval 0 ≤ θ ≤ 2π, (-*i)[sup]i[/sup] ≠ i[sup]i[/sup]*, so I will conclude that your *n* should be 2*n*.

*Last edited by Zhylliolom (2006-07-13 10:07:19)*

Offline

**Ricky****Moderator**- Registered: 2005-12-04
- Posts: 3,791

sin(3pi/2) doesn't equal 1, does it...

"In the real world, this would be a problem. But in mathematics, we can just define a place where this problem doesn't exist. So we'll go ahead and do that now..."

Offline

**George,Y****Member**- Registered: 2006-03-12
- Posts: 1,316

Hey you guys are discussing something too difficult here!

Though I read it too.

Mathsisfun is good at fun maths and perhaps he is the best person you can consult to.

**X'(y-Xβ)=0**

Offline

**RauLiTo****Member**- From: Bahrain
- Registered: 2006-01-11
- Posts: 142

thank you alot guys

mr.mathisfun ... i think u have got alot of these topics ... i really like them

can i see more ?

ImPo$$!BLe = NoTH!nG

Go DowN DeeP iNTo aNyTHinG U WiLL FinD MaTHeMaTiCs ...

Offline

**Devantè****Real Member**- Registered: 2006-07-14
- Posts: 6,400

Or you could just try looking in the Exercises forum. We're adding some every now and then, so check back regularly!

*Last edited by Devantè (2009-02-14 11:18:30)*

Offline

Pages: **1**