Planck radiation
From specialfunctionswiki
The Planck radiation function is given by $$f(x)=\dfrac{15}{\pi^4} \dfrac{1}{x^5 (e^{\frac{1}{x}}-1)}$$
The Planck radiation function is given by $$f(x)=\dfrac{15}{\pi^4} \dfrac{1}{x^5 (e^{\frac{1}{x}}-1)}$$