Math Is Fun Forum
  Discussion about math, puzzles, games and fun.   Useful symbols: √ ∞ ≠ ≤ ≥ ≈ ⇒ ∈ Δ θ ∴ ∑ ∫ π -

Login

Username

Password

Not registered yet?

Post a reply

Go back

Write your message and submit
:) :| :( :D :o ;) :/ :P :lol: :mad: :rolleyes: :cool: | :dizzy :eek :kiss :roflol :rolleyes :shame :down :up :touched :sleep :wave :swear :tongue :what :faint :dunno
Options

Go back

Topic review (newest first)

mathsyperson
2005-12-01 08:56:26

The second one is trickier.

Let's churn out the first few values and see how they relate to each other.

C_0 = 1
C_1 = 3
C_2 = 1
C_3 = 3
and so on.

These give differences of 2, -2, 2, -2... so we need a function of n that gives that. That can be done by using a variation of the original formula.

C_(n+1) = C_n - 2*(-1)^C_n

MathsIsFun
2005-12-01 07:23:09

A bit hard to write that "n" in the right spot in C-sub-n ... Perhaps if you write C_n.

Anyway, I can do the first one easily:

C_n = n²

(a) C_1 = 1
(b) C_n = C_(n-1) +2(n-1) + 1

Let's check:

C_1 = 1
C_2 = 1 + 2(2-2) + 1 = 4
C_3 = 4 + 2(3-1) + 1 = 9
etc ...

coolwind
2005-11-30 23:33:44

Give a recursive definition
ex:
Cn=7n

(a)C1=7;
(b)Cn+1=Cn+7;

=====
problem:
1.Cn=n^2      2.Cn=2-(-1)^n    ????



thanks!!

Board footer

Powered by FluxBB