Calculus: Differentiability and Curve Properties - Class XI
Comprehensive quiz covering tangents, normals to curves, and function differentiability concepts including piecewise functions, derivatives at boundary points, and implicit differentiation.
Questions
If slope of tangent of curve $y=\dfrac{x}{b-x}$ at $(1,1)$ be $2$ then $b=$
- $1$
- $2$
- $0$
- $-1$
- $-2$
The general solution of the differential equation $\sin{2x}\left( \cfrac { dy }{ dx } -\sqrt { \tan { x } } \right) -y=0$ is $y\phi(x)=x+c$ then ${ \Phi }^{ 1 }\left( \cfrac { \pi }{ 4 } \right) $ is _____
- $1$
- $-1$
- $\cfrac{1}{\sqrt{3}}$
- $\sqrt{-3}$
The derivative of a differentiable even function is always an even function.
- True
- False
If $g$ is the inverse of $f$ and $\displaystyle f'\left( x \right) =\frac { 1 }{ 1+{ x }^{ 3 } } $, then $g'\left( x \right) $ is equal to
- $1+{ \left[ g\left( x \right) \right] }^{ 3 }$
- $\displaystyle \frac { 1 }{ 1+{ \left[ g\left( x \right) \right] }^{ 3 } } $
- ${ \left[ g\left( x \right) \right] }^{ 3 }$
- None of these
If $y=mx+c$ is the normal at a point $(8,8)$ on the parabola ${ y }^{ 2 }=8x$ Find $m$
- $-2 $
- $8 $
- $10 $
- $16 $
Function $ f(x)= \sin^{-1} (3x-4x^3) $ is-
- Always differentiable
- Not differentiable at 2 points
- Not continuous at 2 points
- Not differentiable at 3 points
If $\log \sqrt{x^2+y^2}=\tan^{-1}\left(\dfrac{y}{x}\right)$ , then $\dfrac{dy}{dx}$ is:
- $1$
- $2$
- $\dfrac{2x}{\sqrt{x^2+y^2}}$
- $\dfrac{x+y}{x-y}$
If $y = \left| {\cos x} \right| + \left| {\sin x} \right|$ , then ${\dfrac{dy} {dx}}$ at $x = {\dfrac {2\pi } 3}$ is
- ${1 \over 2}\left( {\sqrt 3 + 1} \right)$
- $2\left( {\sqrt 3 - 1} \right)$
- ${1 \over 2}\left( {\sqrt 3 - 1} \right)$
- none of these
The line $y =\sqrt{2}x + 4\sqrt{2}$ is a normal to $y^{2} =4ax$ then a =
- $2$
- $\sqrt{2}$
- $1$
- $-1$
The number of points where $f(x) = \mid | x |^2 - 5| x | + 6 \mid $ is non-derivable is/are
- 1
- 3
- 4
- 5
- True
- False
Let $f(x) = \left{\begin{matrix} 2 + 1,& x \leq 1\ x^{2} + 2, & 1 < x \leq 2\ 4x - 2, & x > 2\end{matrix}\right.$ then the number of points where $f(x)$ is non-differentiable, is equal to
- $0$
- $1$
- $2$
- $3$
$f(x)=|\cos x|$ is not differentiable for the points given by $x=?$
- $\dfrac{\pi}{2}$
- $(2n+1)\pi, \forall n\in I$
- $(2n+1)\dfrac{\pi}{2}\forall n\in I$
- $0$
If $g$ is the inverse of $f$ and $f'(x)=\dfrac{1}{1+x^{3}}$, then $g'(x)$ is equal to.
- $1+[g(x)]^{3}$
- $\dfrac{1}{1+[g(x)]^{3}}$
- $[g(x)]^{3}$
- $None\ of\ these$
If $f(x)=(x^2-4)\left|x^3-6x^2+11x-6\right|+\dfrac{x}{1+|x|}$, then the set of points at which the function $f(x)$ is not differentiable is?
- $\{-2, 2, 1, 3\}$
- $\{-2, 0, 3\}$
- $\{-2, 2, 0\}$
- $\{1, 3\}$
If $\sqrt { { x }^{ 2 }+{ y }^{ 2 } } ={ e }^{ t }$ where $t=\sin ^{ -1 }{ \left( \cfrac { y }{ \sqrt { { x }^{ 2 }+{ y }^{ 2 } } } \right) } $ then $\cfrac { dy }{ dx } $ is equal to
- $\cfrac { x-y }{ x+y } $
- $\cfrac { x+y }{ x-y } $
- $\cfrac { y-x }{ y+x } $
- $\cfrac { x-y }{ 2x+y } $
Value of c is :-
$\dfrac{d}{dx}(c\ ^{f(x)}) = f' (x)e^{f(x)}$
- $e$
- $e^2$
- $1$
- $ln{x}$
The condition that the line $\dfrac{x}{a}+\dfrac{y}{b}=1$ is tangent to the curve $x^{2/3}+y^{2/3}=1$ is
- $a^{2}+b^{2}=2$
- $a^{2}+b^{2}=1$
- $\dfrac{1}{a^{2}}+\dfrac{1}{b^{2}}=1$
- $a^{2}$
If line $PQ$, whose equation is $y = 2x + k,$ is a normal to the parabola whose vertex is $(-2,3)$ and the axis parallel to the $x$-axis with latus rectum equal to $2$, then the possible value of k is
- $\dfrac{{58}}{8}$
- $\dfrac{{50}}{8}$
- $1$
- $-1$
If $y = \dfrac { 1 } { 1 + x ^ { n - m } + x ^ { p - m } } + \dfrac { 1 } { 1 + x ^ { m - n } + x ^ { p - n } } + \dfrac { 1 } { 1 + x ^ { m - p } + x ^ { n - p } }$ then $\dfrac { d y } { d x }$ at $x = e ^ { m ^ { n p } }$ is equal to
- $e ^ { m n p }$
- $e ^ { m n / p }$
- $e ^ { n p / m }$
- $0$
Let f(x) be a differentiable function and $f\left( \alpha \right) = f\left( \beta \right) = 0,\left( {\alpha < \beta } \right)$, then in the interval $\left( {\alpha ,\beta } \right)$
- $f\left( x \right) + f'\left( x \right) = 0$ has at least one root.
- $f\left( x \right) - f'\left( x \right) = 0$ has at least one root.
- $f\left( x \right) . f'\left( x \right) = 0$ has at least one root.
- None of these
If $y = \log \left( \frac { 1 + x } { 1 - x } \right) ^ { 1 / 4 } - \frac { 1 } { 2 } \tan ^ { - 1 } x ,$ then $\frac { d y } { d x } =$
- $\frac { x ^ { 2 } } { 1 - x ^ { 4 } }$
- $\frac {2 x ^ { 2 } } { 1 - x ^ { 4 } }$
- $\frac { x ^ { 2 } } { 2 \left( 1 - x ^ { 4 } \right) }$
- None of these
If f'$\left( x \right) =\sqrt { { 2x }^{ 2 }-1 } $ and y=f$\left( { x }^{ 2 } \right) $ then $\dfrac { dy }{ dx } $ at x=1 is
- 2
- 1
- -2
- none of these
A differentiable function function $y = h(x)$ satisfies $\displaystyle \overset{x}{\underset{0}{\int}} (x - t + 1)h(t)dt = x^4 + x^2; \forall x \ge 0$, then value of $h(0) + h'(0)$ is equal to
- $0$
- $1$
- $e^2$
- $2$
Area of the triangle formed by the lines $x-y=0, x+y=0$ and ant tangent to the hyparabola $x^{2}-y^{2}=a^{2}$ is
- $|a|$
- $\dfrac{1}{2}|a|$
- $a^{2}$
- $\dfrac{1}{2}a^{2}$
If $x = \exp \left{ \tan ^ { - 1 } \left( \frac { y - x ^ { 2 } } { x ^ { 2 } } \right) \right}$ then $\frac { d y } { d x } =$
- $2 x [ 1 + \tan ( \log x ) ] + x \cdot \sec ^ { 2 } ( \log x )$
- $x [ 1 + \tan ( \log x ) ] + \sec ^ { 2 } ( \log x )$
- $2 x [ 1 + \tan ( \log x ) ] + x ^ { 2 } \sec ^ { 2 } ( \log x )$
- None of these
Consider the function $f(x)=\mathrm{s}\mathrm{g}\mathrm{n} x$ and $g(x)=x\left ( 1-x^{2} \right )$. Which of the following does NOT hold good?
- $(fog)(x)$ is neither odd nor even
- $(gof)(x)$ is odd
- $(fog)(x)$ is neither continuous nor differentiable for some $x$ on $\left ( -\infty, \infty \right )$
- $(fog)(x)$ is continuous and differentiable for every $x$ on $\left ( -\infty, \infty \right )$
The set of all points of differentiability of the function $\displaystyle f(x) = \dfrac{\sqrt{x + 1} 1}{\sqrt{x}}$ for $x$ and $f(0)$ = 0 is
- $(\infty , \infty)$
- $[0 , \infty)$
- $(0 , \infty)$
- $(\infty$ , $\infty)$ $-\left \{ 0 \right \}$
If the graph of the equation $y = 2x^2 - 6x + C$ is tangent to the $x$-axis, the value of $C$ is
- $3$
- $3\dfrac{1}{2}$
- $4$
- $4\dfrac{1}{2}$
- $5$
$f\left( x \right) =\begin{cases} x;\quad x<1 \ 3-x;\quad 1\le x\le 3 \end{cases}$ then $f^{'}(x)=$
- $2$
- $0$
- $-1$
- Does not exist
The domain of the derivative of the function
$\displaystyle f\left ( x \right )=\begin{cases}
\tan^{-1}x & \text{ if } \left | x \right |\leq 1 \
\frac{1}{2}\left ( \left | x \right |-1 \right ) & \text{ if } \left | x \right |> 1
\end{cases}$
- $R\sim \left \{ 0 \right \}$
- $R\sim \left \{ 1 \right \}$
- $R\sim \left \{ -1 \right \}$
- $R\sim \left \{ -1, 1 \right \}$
Let $f(x)=ax^2+bx+c$ such that $f(1)=f(-1)$ and a, b, c are in Arithmetic Progression.
- A.P.
- G.P.
- H.P.
- Arithmetico-geometric progression
If $y=\displaystyle\dfrac{1}{a-z}$, then $\displaystyle\dfrac{dz}{dy}$ is:
- $(a-z)^2$
- $-(z-a)^2$
- $(z+a)^2$
- $-(z+a)^2$
Which of the following given statements is/are correct?
- If L.H.D $\neq $ R.H.D, then $f(x)$ is not differentiable at $x= c$
- If a function is differentiable at a point, it is necessarily continuous at the point.
- If a function is differentiable at each $x \in R$ then it is said to be every where differentiable.
- $\dfrac{d}{dx}(c f (x)) =c \dfrac{d}{dx} (f (x))$, where $c$ is a constant.
The value of $\displaystyle \frac{d}{dx} (|x-1|+ |x-5|) $ at x = 3 is
- -2
- 0
- 2
- 4
Let $f : R \rightarrow R$ be a function defined by $f(x)= \max\left { x, x^3 \right }$. The set of all points where $f(x)$ is NOT differentiable is:
- $\{-1, 1\}$
- $\{-1, 0\}$
- $\{0, 1\}$
- $\{-1, 0, 1\}$
If $f(x) = \left{\begin{matrix}e^x+ax & x< 0 \ b(x-1)^2 & x \geq 0 \end{matrix}\right.$ is differentiable at $x= 0$, then $(a, b)$ is
- $(-3, -1)$
- $(-3, 1)$
- $(3, 1)$
- $(3, -1)$
If $f(x) =x[x \sqrt{x}-\sqrt{x+1}]$, then:
- $f(x)$ is continuous but not differentiable at $x= 0$
- $f(x)$ is not differentiable at $x= 0$
- $f(x)$ is differentiable at $x= 0$
- none of these
If $y = \dfrac {1}{1 + x^{n - m} + x^{p - m}} + \dfrac {1}{1 + x^{m - n} + x^{p - n}} + \dfrac {1}{1 + x^{m - p} +x^{n - p}}$ then $\dfrac {dy}{dx}$ at $e^{m^{n^{p}}}$ is equal to
- $e^{mnp}$
- $e^{mn/p}$
- $e^{np/m}$
- $0$
If the distance between a tangent to the parabola $y^{2} = 4x$ and a parallel normal to the same parabola is $2\sqrt{2}$, then possible values of gradient of either of them are:
- $-1$
- $+1$
- $-\sqrt{\sqrt{5} - 2}$
- $+\sqrt{\sqrt{5} - 2}$
Consider the function $f(x)=\begin{cases} x^2 \sin \dfrac{1}{x};x\neq 0 \ 0 ; otherwise \end{cases}$
then,
- $f$ is derivable at $x=0$
- $f $ is not derivable at $x=0$
- $f$ is derivable at $x=0$ and $f'(0)=0$
- $f$ is derivable at $x=0$ and $f'(0)\neq0$
Consider the following statements:
$1.$ Derivative of $f(x)$ may not exist at some point.
$2.$ Derivative of $f(x)$ may exist finitely at some point.
$3.$ Derivative of $f(x)$ may be infinite (geometrically) at some point.
Which of the above statements are correct?
- $1$ and $2$ only
- $2$ and $3$ only
- $1$ and $3$ only
- $1, 2$ and $3$
- $5$
- $3$
- $\dfrac{1}{5}$
- None of these
A function is defined in $(0, \infty)$ by
$f(x) = \left{\begin{matrix}1 - x^{2} & for & 0 < x \leq 1\ \ln\ x & for & 1 < x \leq 2\ \ln\ 2 - 1 + 0.5x & for & 2 < x < \infty\end{matrix}\right.$
Which one of the following is correct in respect of the derivative of the function, i.e., $f'(x)$?
- $f'(x) = 2x$ for $0 < x \leq 1$
- $f'(x) = -2x$ for $0 < x \leq 1$
- $f'(x) = -2x$ for $0 < x < 1$
- $f'(x) = 0$ for $0 < x < \infty$
is everywhere differentiable. Then value of constant $a$ is
- $3$
- $\dfrac{1}{3}$
- $5$
- None of these
lf $\mathrm{f}(\mathrm{x})=\left{\begin{array}{l}1, \mathrm{x}<0\1+ \mathrm{s}\mathrm{i}\mathrm{n}\mathrm{x}, 0\leq \mathrm{x}</\pi _{2} \end{array}\right.$, then derivative of f(x) at$\mathrm{x}=0$
- is equal to 1
- is equal to 0
- is equal to -1
- does not exist
If $f(x)=(4+x)^{n}$,$n \epsilon N$ and $f^{r}(0)$ represents the $r^{th}$ derivative of f(x) at x = 0, then the value of $\sum _{r=0}^{\infty}\frac{(f^{r}(0))}{r!}$ is equal to
- $2^{n}$
- $e^{n}$
- $5^{n}$
- $4^{n}$
Let $f(x)=\begin{cases}\begin{matrix} 1 & \forall & x<0 \ 1+\sin x & \forall & 0\leq x\leq \dfrac{\pi}2\end{matrix}\end{cases}$ then what is the value of $f'(x)$ at $x=0?$
- $1$
- $-1$
- $\infty$
- Does not exist
The second order differential equation is :
- ${ y' }^{ 2 }+x={ y }^{ 2 }$
- $y'+y''+y=\sin { x } $
- $y'''+y''+y=0$
- $y'=y$
$f\left( x \right) = \left| {x - 1} \right| + \left| {x + 2} \right| + \left| {x - 3} \right|$ is not differentiable at
- 2 points
- 3 points
- 4 points
- 1 point