Let g be the function defined on the set of all real numbers by
问题描述：
Let g be the function defined on the set of all real numbers by
(继续) g(x)=1 if x is rational and g(x)=e^x if x is irrational.Then the set of numbers at which g is continuous is
(a)the empty set
(b){0}
(c){1}
(d)the set of rational numbers
(e)the set of irrational numbers
为什么选b?
答
x=0,e^x=1,此时函数连续