Obtaining Formula from Graph

S

sequoia22

New member
Joined
Mar 29, 2009
Messages
8
So there is this graph. It will go up one point, move a distance horizontally, and then go up one point. Then, it will double its horizontal distance, and move up one again. It will double its last horizontal distance, and it will continue. How do i express this??? I have been working a few hours and cant seem to find it. I have tried recursive, summation....I'm lost. I even tried to regress it on my ti - 83, but the results were unpromising.
Here are some coordinates.

at point 0 its 0
at 1 its 1
at 2 its 2
at 3 its 2
4 its 3
(5,3)
(6,3)
(7,3)
(8, 4)
(9,4)
(10,4)
(11,4)
(12, 4)
(13, 4)
(14, 4)
(15, 4)
(15, 4)
(16, 5)
and so on. for every change in y, the x will double its previous distance. How do i express it with a formula?

Please help
 
sequoia22 said:
So there is this graph. It will go up one point, move a distance horizontally, and then go up one point. Then, it will double its horizontal distance, and move up one again. It will double its last horizontal distance, and it will continue. How do i express this??? I have been working a few hours and cant seem to find it. I have tried recursive, summation....I'm lost. I even tried to regress it on my ti - 83, but the results were unpromising.
Here are some coordinates.

at point 0 its 0
at 1 its 1
at 2 its 2
at 3 its 2
4 its 3
(5,3)
(6,3)
(7,3)
(8, 4)
(9,4)
(10,4)
(11,4)
(12, 4)
(13, 4)
(14, 4)
(15, 4)
(15, 4)
(16, 5)
and so on. for every change in y, the x will double its previous distance. How do i express it with a formula?

Please help
Click to expand...

What are the types of functions do you know about?

Do you know about Integer Floor function?

For a quick review go to:

http://mathworld.wolfram.com/FloorFunction.html
 
I know about the floor function, and have been trying to make a recursive floor function of some type. I haven't had much luck.

So its a floor function that doubles its x distance for every change in y. Or every time x double y will increase by 1.

How would I create a step functions who's steps double every time?
 
sequoia22 said:
I know about the floor function, and have been trying to make a recursive floor function of some type. I haven't had much luck.

So its a floor function that doubles its x distance for every change in y. Or every time x double y will increase by 1.

How would I create a step functions who's steps double every time?
Click to expand...

Read the article in website I referred to - it should guide you.

If you look at the values of [LOG[sub:39fj2xry]2[/sub:39fj2xry](x) + 1] - what do you get?
 
Confused, one more question.

Been a while since i used logarithms.

[LOG2(x) + 1] = (in a ti-83) = {log( x +1) /log (2)}

If that's the case, the values i get almost fit it. They do the kind of step function increase, buts its off. I need one that follows the system below. What part of the formula would i tweak to make that work?

(0,0)
(1, 1)
(2,2)
(3, 2)
(4, 3)
(5,3)
(6,3)
(7,3)
(8, 4)
(9,4)
(10,4)
(11,4)
(12, 4)
(13, 4)
(14, 4)
(15, 4)
(15, 4)

I need to figure our how to get the log formula to express those.
 
O! i add the one outside the brackets. That makes sence. Thanks for all the help!
 
You must log in or register to reply here.
Top