If f(x) = begin{cases} x^{alpha} sin left( fr | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(C) Given,$f(x) = \begin{cases} x^{\alpha} \sin \left( \frac{1}{x} ight) ; & x 
eq 0 \ 0 ; & x = 0 \end{cases}$ For continuity at $x = 0$,$\lim_{x

Vedclass · Accepted Answer

$f(x)$ is continuous and differentiable for $\alpha > 1$

Vedclass · Answer

(C) Given,$f(x) = \begin{cases} x^{\alpha} \sin \left( \frac{1}{x} ight) ; & x 
eq 0 \ 0 ; & x = 0 \end{cases}$ For continuity at $x = 0$,$\lim_{x ightarrow 0} f(x) = f(0) = 0$. $\lim_{x ightarrow 0} x^{\alpha} \sin \left( \frac{1}{x} ight) = 0$ only if $\alpha > 0$. Thus,$f(x)$ is continuous for $\alpha > 0$. For differentiability at $x = 0$,$f^{\prime}(0) = \lim_{h ightarrow 0} \frac{f(0 + h) - f(0)}{h} = \lim_{h ightarrow 0} \frac{h^{\alpha} \sin \left( \frac{1}{h} ight) - 0}{h} = \lim_{h ightarrow 0} h^{\alpha - 1} \sin \left( \frac{1}{h} ight)$. This limit exists and is equal to $0$ if $\alpha - 1 > 0$,i.e.,$\alpha > 1$. Therefore,$f(x)$ is continuous and differentiable for $\alpha > 1$.

If $f(x) = \begin{cases} x^{\alpha} \sin \left( \frac{1}{x} \right), & x \neq 0 \\ 0, & x = 0 \end{cases}$; Which of the following is true?

Similar Questions

If $f(x) = a|\sin x| + be^{|x|} + c|x|^3$,where $a, b, c \in \mathbb{R}$,is differentiable at $x = 0$,then:

The number of points at which the function,$f(x) = |x - 0.5| + |x - 1| + \tan x$ does not have a derivative in the interval $(0, 2)$ is :

If $f(x)$ is a differentiable function such that $f: R \to R$ and $f\left( \frac{1}{n} \right) = 0$ for all $n \ge 1, n \in I$,then:

Let $g(x) = x \cdot f(x)$,where $f(x) = \begin{cases} x \sin \frac{1}{x}, & x \ne 0 \\ 0, & x = 0 \end{cases}$. Discuss the differentiability of $g$ at $x = 0$.

Let $f(x) = \begin{cases} 1, & \forall x < 0 \\ 1 + \sin x, & \forall 0 \le x \le \pi/2 \end{cases}$,then what is the value of $f'(x)$ at $x = 0$?

Vedclass Test Series

Exam Paper Generator

Online Exam Module