If function , then is continuous at ..... number of…

MATHEMATICS · Single correct · CBSE · Mathematics · Continuity and Differentiability · Continuity and Differentiability

Problem

If function

f(x) = \begin{cases} x, & \text{if } x \text{ is rational} \\ 1-x, & \text{if } x \text{ is irrational} \end{cases}

, then

f(x)

is continuous at ..... number of points (a)

\infty

(b) 1 (c) 0 (d) None of these