Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Continuity and Differentiability

Question:

The function $f(x) = \left\{\begin{matrix} \frac{x^2+2x-3}{x-1} & x ≠ 1\\2 & x=1\end{matrix}\right.$ is :

Options:

continuous at x=1 only

discontinuous at x=1 only

continuous at every real number

discontinuous at every real number

Correct Answer:

discontinuous at x=1 only

Explanation:

The correct answer is Option (2) → discontinuous at x=1 only

$f(1)=2$

$\lim\limits_{x→1}\frac{x^2+2x-3}{x-1}=\lim\limits_{x→1}\frac{(x-1)(x+3)}{(x-1)}$

$=\lim\limits_{x→1}x+3=4≠2$

discontinuous at $x=1$