Find f(x) from z to z if f(3)=70, f(4)=180, f(5)=470, ...

[tony123]

f (x) function from z to z
x is integer
f(3)=70, f(4)=180,f(5)=470, f(6)=1230
find f(x)

 

[stapel]

f (x) function from z to z
x is integer

Does "from z to z" mean "from the integers to the integers", or "\(\displaystyle \L f\, :\,\mathbb{Z} \rightarrow \mathbb{Z}\)"?

f(3)=70, f(4)=180,f(5)=470, f(6)=1230 find f(x)

Does this mean that you are needing to find some integer function which takes on only integral values, and passes through the above points?

Thank you!

Eliz.

 

[skeeter]

used technology and got a cubic polynomial function to fit ... it isn't pretty.

 

[Deleted member 4993]

If you take 'ln' of both sides - a linear relationship results

ln[f(x)] = 4.106 * ln(x) -0.3649

ugly but good correlation. Of course, it does not return integer values.