Dirichlet function On Baidu Encyclopedia The Dirichlet function over the real number field is expressed as: D(x)=lim(n→∞){lim(m→∞)[cosπm!x]^n}  (1)  It can also simply express the form of piecewise function d (x) = 0 (x is irrational) or 1 (x is rational) (2) The process of finding (1) and pushing (2)

Dirichlet function On Baidu Encyclopedia The Dirichlet function over the real number field is expressed as: D(x)=lim(n→∞){lim(m→∞)[cosπm!x]^n}  (1)  It can also simply express the form of piecewise function d (x) = 0 (x is irrational) or 1 (x is rational) (2) The process of finding (1) and pushing (2)

A little difficult