# Help with a loglogplot in maple please

1. Feb 21, 2009

### elarson89

Help with a loglogplot in maple please!!!

Hi all,

I have some physics homework that I'm trying to finish tonight. I have it all done and everything, and now all i have to do is make a plot. I'm trying to do a loglogplot of Planck's Law. Here's my code:

with(plots);

c:=2.998*10^8;
k:=1.381*10^(23);
h:=6.626*10^(-34);
t:=4500;

Plancks_Law:=x->(8*Pi*h/(c^3))*(x^3/(exp(h*x/(k*t))-1));

and all i'm doing to try to plot is, loglogplot(Plancks_Law(x),x=1..10000);

I don't care what the domain is, but anything i try gives me an empty plot error. Any suggestions??

Thanks

2. Feb 21, 2009

### CompuChip

Re: Help with a loglogplot in maple please!!!

I think you have some constants wrong.
When I evaluate h / (k t) with your numbers, I get something like 10-60 while it should be like 10-14.
As a consequence, unless you take x = 1060, your exponential will be very close to 1, so your denominator becomes 1 - 1 = 0.

Follow-up: try k:=1.381*10^(-23) instead of k:=1.381*10^(23).

3. Feb 21, 2009

### elarson89

Re: Help with a loglogplot in maple please!!!

genius!! I had boltzmann's constant to be of order 10^23, not 10^-23. Thanks a ton!