Which expansion is used for this result?

[rwooduk]

exp (hv/kT) - 1



For hv<<kT



exp (hv/kT) - 1 is approximately equal to hv/kT


thanks for any ideas.

 

[mfb]

How many expansions do you know?

exp(x) ~ 1+x should look familiar.

 

[rwooduk]

How many expansions do you know?

exp(x) ~ 1+x should look familiar.

ahh yes i know this result thanks!

its the Maclaurin series...

http://en.wikipedia.org/wiki/Taylor_series#List_of_Maclaurin_series_of_some_common_functions

missed this in the first year!

thanks again