Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Continuity and Differentiability

Question:

$\underset{x→1}{\lim}(x-1)\{x\}$, where {.} denotes the fractional part, is equal to:

Options:

1

0

does not exist

None of these

Correct Answer:

0

Explanation:

LHL = $\underset{h→0}{\lim}(1-h-1)\{1-h\}$

$=\underset{h→0}{\lim}(-h)\{1-h\}=0$

RHL = $\underset{h→0}{\lim}(1+h-1)\{1+h\}$

$=\underset{h→0}{\lim}h^2=0$

As LHL = RHL = 0, limiting value = 0