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General => Off topic => Topic started by: Joka X on July 25, 2009, 08:46:11 pm



Title: Math
Post by: Joka X on July 25, 2009, 08:46:11 pm
can someone explain in details, what are number patterns? please~~ before Thursday....


Title: Re: Math
Post by: Joka X on July 26, 2009, 06:17:52 am
come on.....  Exploited~~~


Title: Re: Math
Post by: Exploited on July 27, 2009, 12:58:30 am
OK... Number patterns is when you have some numbers one after another and you have a formula for finding the next number after them.

Example 1:

1, 2, 3, 4, 5, 6 ...

in that case:
a1 = 1
a2 = 2
a3 = 3
...
a(n) = a(n-1)+1

So if you wish to find how much is a100 you know it directly:

a100 = a99 + 1 = 99 +1

Another example:

an = 2*a(n-1) +2
a0 = 1

Find how much is a3.

Well, not too hard.

a1 = 2*a0 + 2
=> a1 = 2*1 + 2 = 4

a2 = 2*a1 + 2
=> a2 = 2*4 + 2 = 10

a3 = 2*a2 + 2
=> a3 = 2*10 + 2 = 22

=> we have the following pattern:

1, 4, 10, 22, 46, 94, ...


Most of the problems are like the first example: "Find the pattern formula from the following numbers...".


Title: Re: Math
Post by: tegezan on July 27, 2009, 03:11:59 am
I hate math.. :P


Title: Re: Math
Post by: Joka X on July 27, 2009, 05:30:00 am
thank you for helping me with my assignment expanding my knowledge :)

I hate math.. :P

I hate math too, but I still need to study it T.T


Title: Re: Math
Post by: tegezan on July 27, 2009, 05:56:06 am
dont be lazy like me.. :P


Title: Re: Math
Post by: keaglez on July 27, 2009, 07:54:11 am
Math is fun...., sometime... :D


Title: Re: Math
Post by: Exploited on July 27, 2009, 09:00:47 am
You must learn everything without loosing parts of it and then it will be easy discipline. Actually much easier than others.


Title: Re: Math
Post by: Phantom2009 on July 27, 2009, 11:33:46 am
Must serious to learn it


Title: Re: Math
Post by: ahmed on July 27, 2009, 11:34:30 am
math is my best subject so far since i was in primary school..
we call (number patterns) as sequences too... :)


Title: Re: Math
Post by: Joka X on August 12, 2009, 08:29:37 pm
Dear Exploited, please explain in details about negative number and everything related to it. thank you.


Title: Re: Math
Post by: NiKSY on August 13, 2009, 01:33:22 am
Before I write anything, I want to say that I DO NOT WANT TO INSULT ANYONE. It's just interesting to me how different is the education in different countries...

You are 17 now? So am I... You really never learned anything about negative numbers in school so far? Not in primary school? Not yet in high school?
I can't remember when did we first started doing equations with them... Was it in 5th grade... 0.o Thats 11 years...


Title: Re: Math
Post by: Joka X on August 13, 2009, 02:09:20 am
I have... but I need to do a presentation, so any info would help me to explain it in details.... beside, I dont have my reference book with me (I'm not staying in my home now). Yes, I know what negative number is, but how do I explain it in a way so that others will understand? so I need some guide, yes, there are info on net, but it wont hurt asking for more info.


Title: Re: Math
Post by: ahmed on August 13, 2009, 03:26:43 pm
U mean true numbers? which contain both negative and positive numbers including zero...so...remembering... when summing some negative numbers [(-2)+(-3)+(-5)+(-8)]=[-(2+3+5+8)]=-18...so excluding the negative sign then sum the numbers as positive ones then we put the negative sign to final result..
when summing  negative and positive numbers  we substrate (lower number from higher one)and the final result will take the sign[whether (+) or (-)] of the higher number (-15)+(10)=[-(15-10)]=-5...(-20)+(35)=[+(35-20)]=+15=15..(-5)+(-9)+(6)+(7)=[(-14)+(13)]=[-(14-13)]=(-1) in multiply take this (Negative*Negative)=positive....(-5)*(-6)=+30=30... (Negative*positive)=Negative ..(-2)*(4)=(-8) the same way in dividing operation...negative/negative=positive....positive/negative=negative.. negative/positive=negative..(-8)/(2)=(-4)..(-25)/(-5)=5.. i hope that would explain something to u  :)