MathDB
Nice primitivability result

Source:

December 14, 2019
functionprimitivesreal analysis

Problem Statement

Consider a function f:RR f:\mathbb{R}\longrightarrow\mathbb{R} that admits bounded primitives. Prove that the function g:RR g:\mathbb{R}\longrightarrow\mathbb{R} defined as f(x)={x,emsp;x0f(1/x)lnx,emsp;x>0 f(x)=\left\{ \begin{matrix} x, &   x\le 0 \\ f(1/x)\cdot\ln x ,&   x>0 \end{matrix}\right. admits primitives.
Florian Dumitrel