Help Needed

[Koren The Wanderer]

Could anyone give me a rule for these patterns:
--------------------------------
X | Y
--------------------------------
1 | 5
2 | 13
3 | 23
4 | 35
--------------------------------

Y = ?

[Porter]

--------------------------------
X | Y
--------------------------------
1 | 5 (+8 )
2 | 13 (+10)
3 | 23 (+12)
4 | 35 (+14)
--------------------------------

5 | 49 (+16)
6 | 65 (+18 )
7 | 83

[Koren The Wanderer]

So the rule is?

[Porter]

Can't you see what the rule is?

X = add 1 every time
Y = start by adding 8, add two additionally for every X.

[Koren The Wanderer]

no no. one rule that applies for both. eg;

X Y
1 1
2 4
3 9
4 16
5 25

Y = X squared

[Fitz Tayo]

1 | 5 (+8 )
2 | 13 (+10)
3 | 23 (+12)
4 | 35 (+14)

5 13 23 35
First Differance= 8 10 12
Second Differance= 2 2

Rule: If Second Differance is constant it is quadratic.
If Constant Second Differance is 2, x*x

y=x*x _________

So multiply x by itself.

X*X - D - Y
1 | 4 | 5
4 | 9 | 13
9 | 14 | 23
16 | 19 |35

D=Differance

Differance ascends in 5.

5(x-1) + 4

y=x*x+5(x-1)+4

Proof:

1 | 5 1*1=1 1+5(1-1)=1 1+4=5
2 | 13 2*2=4 4+5(2-1)=9 9+4=13
3 | 23 3*3=9 9+5(3-1)=19 19+4=23
4 | 35 4*4=16 16+5(4-1)=31 31+4=35

There was probably a much easier way to do that. Also put x2 (x squared). I've not idea how to put a square sign in this thing.

EDIT: Sorry 'bout the horrible appearance. All jumbled etc.

[Forerunner]

Woah. Someone knows his shit.

[Flibbo]

1 | 5 (+8 )
2 | 13 (+10)
3 | 23 (+12)
4 | 35 (+14)

5 13 23 35
First Differance= 8 10 12
Second Differance= 2 2

Rule: If Second Differance is constant it is quadratic.
If Constant Second Differance is 2, x*x

y=x*x _________

So multiply x by itself.

X*X - D - Y
1 | 4 | 5
4 | 9 | 13
9 | 14 | 23
16 | 19 |35

D=Differance

Differance ascends in 5.

5(x-1) + 4

y=x*x+5(x-1)+4

Proof:

1 | 5 1*1=1 1+5(1-1)=1 1+4=5
2 | 13 2*2=4 4+5(2-1)=9 9+4=13
3 | 23 3*3=9 9+5(3-1)=19 19+4=23
4 | 35 4*4=16 16+5(4-1)=31 31+4=35

There was probably a much easier way to do that. Also put x2 (x squared). I've not idea how to put a square sign in this thing.

EDIT: Sorry 'bout the horrible appearance. All jumbled etc.

not just a fine piece of ass after all

[Telephalsion]

1 | 5 (+8 )
2 | 13 (+10)
3 | 23 (+12)
4 | 35 (+14)

5 13 23 35
First Differance= 8 10 12
Second Differance= 2 2

Rule: If Second Differance is constant it is quadratic.
If Constant Second Differance is 2, x*x

y=x*x _________

So multiply x by itself.

X*X - D - Y
1 | 4 | 5
4 | 9 | 13
9 | 14 | 23
16 | 19 |35

D=Differance

Differance ascends in 5.

5(x-1) + 4

y=x*x+5(x-1)+4

Proof:

1 | 5 1*1=1 1+5(1-1)=1 1+4=5
2 | 13 2*2=4 4+5(2-1)=9 9+4=13
3 | 23 3*3=9 9+5(3-1)=19 19+4=23
4 | 35 4*4=16 16+5(4-1)=31 31+4=35

There was probably a much easier way to do that. Also put x2 (x squared). I've not idea how to put a square sign in this thing.

EDIT: Sorry 'bout the horrible appearance. All jumbled etc.

I totally knew this, I'm just not that prone to posting a lot.

[Fitz Tayo]

Shit. Sorry I forgot to get the most simple answer.

Screw the whole + 4 business. It's just 5x-1. Whoopsie.

Y = X * X + 5X - 1

Man was that stupid, I've really dodged a bullet there.

[Koren The Wanderer]

Thanks Fitz, you scored me some candy and my name on the great list.

[Fitz Tayo]

All in a days work.

I've gotta revise for my final exams anyway and Mathmatics is one of the subjects I'm taking next year.

[Teenr0cker]

For what, recognising a recursive formula?


Pfft, the one week I leave...