Extrema and nowhere differentiable functions
E. E. Posey, Jerry E. Vaughan · Rocky Mountain Journal of Mathematics · 1986
We give simple, unified constructions of continuous, nowhere differentiable functions that (1) have no proper local maxima or proper local minima, (2) have no proper local maxima but have proper local minima at every point of a dense set, and (3) have proper local maxima at every point of a dense set; and proper local minima at every point of another dense set. Subject classification: 26A15,