# Revision history [back]

### Plot ratio of Bessel functions

Hello! I am new to SageMath and to this page. I'm running SageMath version 9.2, Release Date: 2020-10-24 Using Python 3.8.5..

I tried to define a function as the ratio between the first derivative of bessel_J(1, x) and x*bessel_J(1, x):

f(x) = bessel_J(1, x)

g = derivative(f, x)

h = g / (x*f)

Then, I tried to plot h with:

plot(h, (x, 0, 10))

The result is an empty plot, showing only the x, y axes, and this is not correct.

Am I doing something wrong? Is it possible to plot such a function and, if yes, how?

 2 None slelievre 14659 ●16 ●138 ●289 http://carva.org/samue...

### Plot ratio of Bessel functions

Hello! I am new to SageMath and to this page. I'm running this version:

SageMath version 9.2, Release Date: 2020-10-24 Using Python 3.8.5..

I tried to define a function as the ratio between the first derivative derivative of bessel_J(1, x) and x*bessel_J(1, x):

f(x) = bessel_J(1, x) x)
g = derivative(f, x) x)
h = g / (x*f) 
(x*f) 

Then, I tried to plot h with:

plot(h, (x, 0, 10)) 
10)) 

The result is an empty plot, showing only the x, y axes, and this is not correct.

Am I doing something wrong? Is it possible to plot such a function and, if yes, how?

 3 None slelievre 14659 ●16 ●138 ●289 http://carva.org/samue...

### Plot ratio of Bessel functions

I am new to SageMath and to this page. I'm running this version:

SageMath version 9.2, Release Date: 2020-10-24 Using Python 3.8.5.

I tried to define a function plot the ratio of two functions related to Bessel functions.

First I defined f as the ratio between the first derivative derivative of bessel_J(1, x) and gas x*bessel_J(1, x):

f(x) = bessel_J(1, x)
g = derivative(f, x)


Then I defined h as their ratio:

h = g / (x*f)


Then, I tried to plot h with:

plot(h, (x, 0, 10))


The result is an empty plot, showing only the x, y axes, and this is not correct.

Am I doing something wrong? Is it possible to plot such a function and, if yes, how?