Quantum physics (blackbody radiation)

[HaZe-]

Homework Statement

How to prove the solution to question number 2 equation?

Relevant Equations

Prove it to be like that.. number 2

 

[Charles Link]

See https://www.physicsforums.com/threa...n-plancks-law-derivation.961396/#post-6097855 and the "links" in post 2 of this thread, particularly https://www.physicsforums.com/threa...-density-of-a-black-body.956343/#post-6063569
And please complete the homework template in the future and don't delete it.