MCQ
For which value of $k$, this funciton is continuous at $x=1$.$ f(x)=\left\{\begin{array}{cc} \frac{x^2-3 x+2}{x-1}, & x \neq 1 \\
= k, & x=1 \end{array}\right. $
  • A
    $1$
  • $-1$
  • C
    $0$
  • D
    $3$

Answer

Correct option: B.
$-1$
value of function at $x=1$
$f(1)=k$
Value of $\text{R.H.L.}$
$=\lim _{h \rightarrow 0} f(1+h)$
$=\lim _{h \rightarrow 0} \frac{(1+h)^2-3(1+h)+2}{1+h-1}$
$=\lim _{h \rightarrow 0} \frac{1+2 h+h^2-3-3 h+2}{h}$
$=\lim _{h \rightarrow 0} \frac{h^2-h}{h}$
$=\lim _{h \rightarrow 0}[h-1]$
$=-1$
because function is continuous at $x=1$, so
$f(1)= \text{R.H .L.}$
$\therefore k=-1$
Hence correct option is $(B).$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free