modified Dirichlet function | small Riemann function | Thomae function

Let c and d!=c be real numbers (usually taken as c = 1 and d = 0). The Dirichlet function is defined by D(x) = {c | for x rational d | for x irrational auto right match and is discontinuous everywhere. The Dirichlet function can be written analytically as D(x) = lim_(m->∞) lim_(n->∞) cos^(2n)(m!π x).

continuous function | Dirichlet beta function | Dirichlet eta function | Dirichlet lambda function | Euclid's orchard | irrational number | rational number

Lejeune Dirichlet