Maths C1 Question (sequences)

[Bugz]

Anyone lend a hand with this particular question? The wording for C1 is a total ****:

'The sequence u1, u2, u3, ... is defined by the recurrence relation:

Un + 1 = (Un)(squared) - 1, N is greater than or equal to 1.

Given that u1 = k, where k is a constant

Find expressions for u2 and u3 in terms of k.

 

[Ormorof]

so if n=0 then un+1 = u1? so if n=1 then it would = u2, so k=u1 + n as a general rule? or something like that?

 

[Bugz]

so if n=0 then un+1 = u1? so if n=1 then it would = u2, so k=u1 + n as a general rule? or something like that?

Well, i'm pretty sure for u2:

u2 = k(squared) - 1

I think that one is pretty simple but how the fuck do I find u3 Oo

 

[Jeremiah]

u3 = (u2)squared - 1, and since u2 = "k"squared - 1 then

u3 = ("k"squared -1)squared -1. Are you meant to expand it out?

 

[Mojo]

U2=Shit Band
U4=Math Geeks

 

[Bugz]

u3 = (u2)squared - 1, and since u2 = "k"squared - 1 then

u3 = ("k"squared -1)squared -1. Are you meant to expand it out?

Unfortunately, the C1 paper is very bland.

All the information I gave above was all that is supplied.

Why did u square u2 to find u3?

 

[Solo]

U2=Shit Band
U4=Math Geeks

Regular coke with that please.

 

[Craft]

bastard, i do know it, i just don't want to get my math notes from last year

 

[Jeremiah]

Unfortunately, the C1 paper is very bland.

All the information I gave above was all that is supplied.

Why did u square u2 to find u3?

Well as has been said already u1 = k. And since U1+1 = U1(squared)-1 then this means U2 = k(squared) - 1. So u2+1 = u2(squared) - 1, and so you substitute in what u2 was and you are given u3 = (k(squared) -1)(squared)-1.

You need to square u2 since u2+1 is dependant on the value of u2, which you have already expressed in terms of t. I hope I'm barking up the right tree I hope its not induction you are doing, I am aweful at that

 

[Bugz]

Well as has been said already u1 = k. And since U1+1 = U1(squared)-1 then this means U2 = k(squared) - 1. So u2+1 = u2(squared) - 1, and so you substitute in what u2 was and you are given u3 = (k(squared) -1)(squared)-1.

You need to square u2 since u2+1 is dependant on the value of u2, which you have already expressed in terms of t. I hope I'm barking up the right tree I hope its not induction you are doing, I am aweful at that

Hoorah. That does look very much right. Cheers.

Never been good at AS/A-Level sequences :<

Rep for you ^^

 

[eksdee]

man, maths, what a horrible subject. i don't envy you.

 

[Coldbeard]

and people bitched about football threads!