# A strange function .

1. Dec 1, 2006

### mubashirmansoor

A strange function.....

Last night I was faced with a strange function & I couldn't figure out the eqation of the function hence I thought I can get some help from the math experts over here...

The function passes through these cordinates:

(3,1) (4,1) (5,2) (6,2) (7,3) (8,3) (9,4) (10,4) ..............
it's logicallt very simple to predict it's next terms but I still couldn't find the equation....

I'd be really really glad if someone would help me figure this out...
Tahnks.

2. Dec 1, 2006

### kesh

add two functions. a diagonal ascending one like y = x/2, and an oscilating one like sin. fiddle with coefficients to get it right

3. Dec 1, 2006

### radou

You may want to investigate this: http://mathworld.wolfram.com/LagrangeInterpolatingPolynomial.html" [Broken].

Last edited by a moderator: May 2, 2017
4. Dec 1, 2006

### kesh

trouble with that is it covers a finite number of points. the sequence in the post is infinite

i reckon (2x - 3 - Cos[Pi x])/4 will do it. Cos taking radian arguments. silly errors aside

Last edited by a moderator: May 2, 2017
5. Dec 1, 2006

### Edgardo

Try using the floor function:

$$\left(x, \lfloor \frac{1}{2}\left( x-1 \right) \rfloor \right)$$

That is the function might look like this:

$$f: [3,\infty) \rightarrow \Re; x \mapsto \lfloor \frac{1}{2}\left(x-1\right) \rfloor$$

Last edited: Dec 1, 2006
6. Dec 1, 2006

### mubashirmansoor

Thanks from everybody who posted.
The problem is solved & you were all a great help
Once again Thankyou...

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