Riemann function is almost nowhere differentiable
From specialfunctionswiki
Theorem
The Riemann function is nowhere differentiable except at points of the form $\pi \dfrac{2p+1}{2q+1}$ with $p,q \in \mathbb{Z}$.
The Riemann function is nowhere differentiable except at points of the form $\pi \dfrac{2p+1}{2q+1}$ with $p,q \in \mathbb{Z}$.