The points of discontinuity of the function $f(x)=\frac{1}{x-1}$ if $0 \leq x \leq 2$ $=\frac{x+5}{x+3}…

The points of discontinuity of the function $f(x)=\frac{1}{x-1}$ if $0 \leq x \leq 2$ $=\frac{x+5}{x+3} \quad$ if $\quad 2 < x \leq 4$ in its domain are
  1. x=2 only
  2. x=1, x=2
  3. x=4 only
  4. x=0, x=2

Solution

$\begin{aligned} f(x) &=\frac{1}{x-1}, \text { if } 0 \leq x \leq 2 \Rightarrow f(x) \text { is not defined at } x=1 \\ &=\frac{x+5}{x+3}, \text { if } 2 < x \leq 4 \end{aligned}$ $\lim _{x \rightarrow 2^{-}} f(x)=\frac{1}{2-1}=1 \text { and } \lim _{x \rightarrow 2^{+}} f(x)=\frac{7}{5}$ Thus $f(x)$ is not continuous at $x=2$

Asked in: MHT CET 2020 (16 Oct Shift 1)

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