Integral equation with nested functions (was: Frage im Anhang)

Question in the Attachment.
Hello, maybe someone can help me in answering.

was:

Frage im Anhang

Hallo,
vielleicht kann mir Jemand bei der Beantwortung helfen.

“rk ist dieUnbekannte” ~ rk is the unknown

Google Translate did not know steitig and diffbar.

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It is unlikely you could find a symbolic solution with Mathematica. A numerical solution from iterating is probably feasible.

Hi,

stetig (instead of the typo steitig) means continuous and diffbar is short for “differenzierbar”, i.e. differentiable.

Cheers,

M.

PS: the question is not really Mathematica/Wolfram Language/Wolfram Alpha related.