Differentiability Questions - JEE

Consider the function $f(x) = \max\{\sin x, |\cos x|\}, \forall x \in [0, 2\pi]$. If $n$ is the number of points at which $f(x)$ is non-differentiable, then the value of $n$ is

If $f(x) = \begin{cases} \frac{x \ln(e + \cos x)}{x^2} & x > 0 \\ q & x \leq 0 \end{cases}$ is continuous at $x = 0$, then the value of $\frac{pq+1}{q}$ is

If $y = \tan^{-1}\left(\frac{1}{x^2+1}\right) + \tan^{-1}\left(\frac{1}{x^2+3}\right)$, find $\frac{dy}{dx}$

If $f(n+1) = \dfrac{1}{2}\left\{f(n) + \dfrac{9}{f(n)}\right\}$ where $n \in N$ and $f(n) > 0\ \forall n \in N$ and $\underset{n\to\infty}{\text{Lt}}\ f(n)$ exist then the value of $\underset{n\to\infty}{\text{Lt}}\ f(n) =$

If $f(x)$ is a real valued bijective function satisfying $f'(x) = \sin^2(\sin(x+1))$ and $f(0) = 3$, then the value of $(f^{-1})''(3)$ is equal to:

Let f be a real valued derivable function such that f(x)f(y) = f(x)y + xf(y), ∀x, y ∈ ℝ. If f′(0) = 2, then find $\lim_{x \to 0} \left[\dfrac{f(x)}{\sin x}\right]$. [Note: [ ] represents greatest integer function.]

Let $f$ and $g$ be two functions defined by $f(x)=\begin{cases}x+1, & x<0\\|x-1|, & x\geq0\end{cases}$ and $g(x)=\begin{cases}x+1, & x<0\\1, & x\geq0\end{cases}$. Then $(g\circ f)(x)$ is

Let $f(x)=[x^2-x]+|-x+[x]|$, where $x\in\mathbb{R}$ and $[t]$ denotes the greatest integer less than or equal to $t$. Then, $f$ is

Let $ f(x) = \dfrac{1 - \tan x}{4x - \pi} $, $ x \neq \dfrac{\pi}{4} $, $ x \in \left[0, \dfrac{\pi}{2}\right] $. If $ f(x) $ is continuous in $ \left[0, \dfrac{\pi}{2}\right] $, then $ f\!\left(\dfrac{\pi}{4}\right) $ is

If lim x\to\infty (( e )( 1 - x )) = \alpha , then the value of log e \alpha equals : 1-e e 1+x 1+log \alpha e

If the function 2 ⎧ {sin(k1 + 1)x + sin(k2 - 1)x} , x < 0 ⎪ ⎪ x ⎪ 4, x = 0 f (x) = ⎨ ⎪ ⎪ 2 2+k1 x ⎩ ⎪ log ( ), x > 0 x e 2+k2 x is continuous at x = 0, then k + k is equal to 2 1 2 2

$\displaystyle\lim_{n\to\infty}\left\{\left(2^{1/2}-2^{1/3}\right)\left(2^{1/2}-2^{1/5}\right)\cdots\left(2^{1/2}-2^{1/(2n+1)}\right)\right\}$ is equal to

Evaluate $\lim_{x \to \frac{\pi}{2}} \frac{\tan\left(\frac{x}{2}\right)(1-\sin x)}{(x-2y)^3}$

We have \[\lim_{x \to 1} \left(1 + \frac{a}{x} - \frac{4}{x^2}\right)^{2x} = e^3\] Find the value of $a$.

If $y = e^{ax^{-4x}}$ and $z = e^{-\ cos^{-1}x}$ then $\dfrac{d^2y}{dz^2} = 0$.State whether the statement is true or false.

Find: $\lim_{n \to \infty} \left(\frac{1^{1/x} + 2^{1/x} + 3^{1/x} + \cdots + n^{1/x}}{n}\right)^{nx}$

If $f(1) = g(1) = 2$ and $f'(1)$, $g'(1)$ exist, then evaluate \[\lim_{x \to 1} \frac{f(1)g(x) - f(x)g(1)}{g(x) - f(x)}\]

$\lim_{x \to 0} \frac{2e^{\sin x} - e^{-\sin x} - 1}{x^2 + 2x}$ equals:

If $g(x) = (x^2 + 2x + 3)f(x)$, $f(0) = 5$ and $\displaystyle\lim_{x \to 0}\left(\frac{f(x) - 5}{x}\right) = 4$, then $g'(0)$ is equal to:

The value of $\lim_{x \to 0} \frac{\sin x + \cos(e^x)}{1 + \sin(3x)}$ is equal to

Let $f(x) = 10 - |x - 5|, x \in \mathbb{R}$, then the set of all values of $x$ at which $f(f(x))$ is not differentiable is

Let $f(x) = \sin(\cos^{-1}(\sin x))$ and $g(x) = \cos(\sin^{-1}(\cos x))$. If $S$ is the range of $\dfrac{f'(x)}{g'(x)}$, then $S$ contains:

If $\displaystyle\lim_{x\to0}\dfrac{e^{ax}-\cos(bx)-cxe^{-cx}}{1-\cos(2x)}=17$, then $5a^2+b^2$ is equal to

$\displaystyle\lim_{x\to0}\frac{e-(1+2x)^{\frac{1}{2x}}}{x}$ is equal to

Let $a\in\mathbb{Z}$ and $[t]$ be the greatest integer $\leq t$, then the number of points, where the function $f(x)=[a+13\sin x]$, $x\in(0,\pi)$ is not differentiable, is ____________.

If $\lim_{x \to 1} \dfrac{x^2 - ax + b}{x - 1} = 5$, then $a + b$ is equal to __________.

For each t ∈ R, let [t] be the greatest integer less than or equal to t. Then limx→0+ x 1 x + 2 x + · · · + 15 x : (1) is equal to 15. (2) is equal to 120. (3) does not exist. (4) is equal to 0.

If $f(x) = \{x + \sin x\} + [x - \sin x] + [x]$ where $[y]$ and $\{y\}$ denote greatest integer function and fractional part function of $y$ respectively, then find the number of points of discontinuity in $[0, \pi]$.

If $f(x) = \begin{cases} \sqrt{t+x^2} & x > 0 \\ a & x = 0 \text{ is continuous at } x = 0 \text{ for some constants } a, b \text{ and } c, \text{ then the value of } \frac{abc}{b^2} \text{ is equal to} \\ \frac{c^2+x}{b^2+x^2} & x < 0 \end{cases}$

$\lim_{x \to 0} \dfrac{(1 - \cos 2x)(3 + \cos x)}{x \tan 4x}$ is equal to

Let f : R \rightarrow R be a positive increasing function with $ \lim_{x \to 0} \frac{f(3x)}{f(x)} = 1 $. Then $ \lim_{x \to 0} \frac{f(2x)}{f(x)} = $

Let $f(1^+) = f(1) = f(1^-)$ and $f'(1^-) = f'(1^+)$. Given $f(x) = a + \cos^{-1}(x+b)$ (for $x \geq 1$) and $f(x) = -\dfrac{1}{\sqrt{1-(1+b)^2}}$ type condition at $x=1$, find $\dfrac{a}{b}$.

Set of a for which limx→a([x −5] −[2x + 2]) = 0:

If $x = t^2 + t + 5$ and $y = \sin t$, then $\dfrac{d^2y}{dx^2}$ is:

$f=\min\{1,1+x\sin x\}$ on $[0,2\pi]$. $(m,n)=$

If $ f : R \to R $ is a function defined by \[ f(x) = [x]\cos\left(\frac{2x-1}{2}\right)\pi, \] where $ [x] $ denotes the greatest integer function, then $ f $ is

If $ \lim_{x \to 0} \dfrac{10 - \displaystyle\sum_{k=1}^{10}(\cos kx)}{x^2} = \dfrac{a}{b} $ where a and b are co-prime, then the value of $ (a + b) $ is equal to:

155. The value of $\displaystyle\lim_{x \to 0} \dfrac{\dfrac{x^2}{2} + 1 - \sqrt{1 + x^2}}{\left(\cos x - e^{x^2}\right)\sin(x^2)}$ is equal to:

27. Consider a function $f: R \to R$ such that $f(x) = \begin{cases} \sin(\pi x), & \text{if } x \in \mathbb{Q} \\ \tan(\pi\sqrt{|x|}), & \text{if } x \notin \mathbb{Q} \end{cases}$. If $\displaystyle\lim_{x \to N} f(x)$ exists, then the sum of all positive integers $N < 100$, is equal to:

Let $f:\mathbb{R}-\{0\}\to\mathbb{R}$ be a function satisfying $f\left(\dfrac{x}{y}\right)=\dfrac{f(x)}{f(y)}$ for all $x,y$, $f(y)\ne 0$. If $f'(1)=2024$, then

Let $f(x)=\sqrt{\displaystyle\lim_{r\to x}\left\{\frac{2r^2[(f(r))^2-f(x)f(r)]}{r^2-x^2}-r^3 e^{f(r)/r}\right\}}$ be differentiable in $(-\infty,0)\cup(0,\infty)$ and $f(1)=1$. Then the value of $ea$, such that $f(a)=0$, is equal to ______.

Let $f:[-1,2]\to\mathbb{R}$ be given by $f(x)=2x^2+x+[x^2]-[x]$, where $[t]$ denotes the greatest integer less than or equal to $t$. The number of points, where $f$ is not continuous, is:

If $\alpha=\displaystyle\lim_{x\to0^+}\frac{e^{\sqrt{\tan x}}-e^{\sqrt{x}}}{\sqrt{\tan x}-\sqrt{x}}$ and $\beta=\displaystyle\lim_{x\to0}(1+\sin x)^{\frac{1}{2}\cot x}$ are the roots of the quadratic equation $ax^2+bx-\sqrt{e}=0$, then $12\log_e(a+b)$ is equal to

If $y = \tan^{-1}\!\left(\dfrac{6x-4-4x^2}{1+6x^2+8x^3}\right)$ and $\dfrac{dy}{dx} = \dfrac{A}{1+4x^2}+\dfrac{B}{1+x^2}$... find $24(A+B)$. [Integer type]

196. Let $f$ and $g$ be defined such that $f'(x) = f^2(x) + g^2(x)$ and $g'(x) = 2f(x)g(x) + 1$. If $f(0) = \dfrac{1}{5}$, $g(0) = \dfrac{4}{5}$, then the value of $f\!\left(\dfrac{\pi}{12}\right) + g\!\left(\dfrac{\pi}{12}\right)$ equals:

The value of $\displaystyle\lim_{x\to0}2\left(\frac{1-\cos x\sqrt{\cos 2x}\sqrt[3]{\cos 3x}\cdots\sqrt[10]{\cos 10x}}{x^2}\right)$ is

Let $f:\left[-\dfrac{\pi}{2},\dfrac{\pi}{2}\right]\to\mathbb{R}$ be a differentiable function such that $f(0)=\dfrac{1}{2}$. If $\displaystyle\lim_{x\to0}\dfrac{x\int_0^x f(t)\,dt}{e^{x^2}-1}=\alpha$, then $8\alpha^2$ is equal to:

The value of $\lim_{x \to \frac{\pi}{4}} \frac{\int_2^{\csc^2 x} g(t)dt}{x^2 - \frac{\pi^2}{16}}$ is:

If $\displaystyle\lim_{x\to1}\frac{(5x+1)^{1/3}-(x+5)^{1/3}}{(2x+3)^{1/2}-(x+4)^{1/2}}=\frac{m\sqrt{5}}{n(2n)^{2/3}}$, where $\gcd(m,n)=1$, then $8m+12n$ is equal to

\[\lim_{n \to \infty} \frac{e^n}{\left(1 + \dfrac{1}{n}\right)^{n^2}}\] equals

Differentiability Questions (1063)