LFM Pure and Mechanics

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isi-entrance 2016 Q71 4 marks Definite Integral as a Limit of Riemann Sums View
For each positive integer $n$, define a function $f_n$ on $[0,1]$ as follows: $$f_n(x) = \left\{ \begin{array}{ccc} 0 & \text{if} & x = 0 \\ \sin\frac{\pi}{2n} & \text{if} & 0 < x \leq \frac{1}{n} \\ \sin\frac{2\pi}{2n} & \text{if} & \frac{1}{n} < x \leq \frac{2}{n} \\ \sin\frac{3\pi}{2n} & \text{if} & \frac{2}{n} < x \leq \frac{3}{n} \\ \vdots & \vdots & \vdots \\ \sin\frac{n\pi}{2n} & \text{if} & \frac{n-1}{n} < x \leq 1 \end{array} \right.$$ Then, the value of $\lim_{n \rightarrow \infty} \int_0^1 f_n(x) dx$ is
(A) $\pi$
(B) 1
(C) $\frac{1}{\pi}$
(D) $\frac{2}{\pi}$
isi-entrance 2016 Q71 4 marks Definite Integral as a Limit of Riemann Sums View
For each positive integer $n$, define a function $f _ { n }$ on $[ 0, 1 ]$ as follows: $$f _ { n } ( x ) = \left\{ \begin{array} { c c c } 0 & \text { if } & x = 0 \\ \sin \frac { \pi } { 2 n } & \text { if } & 0 < x \leq \frac { 1 } { n } \\ \sin \frac { 2 \pi } { 2 n } & \text { if } & \frac { 1 } { n } < x \leq \frac { 2 } { n } \\ \sin \frac { 3 \pi } { 2 n } & \text { if } & \frac { 2 } { n } < x \leq \frac { 3 } { n } \\ \vdots & \vdots & \vdots \\ \sin \frac { n \pi } { 2 n } & \text { if } & \frac { n - 1 } { n } < x \leq 1 \end{array} \right.$$ Then, the value of $\lim _ { n \rightarrow \infty } \int _ { 0 } ^ { 1 } f _ { n } ( x ) d x$ is
(A) $\pi$
(B) 1
(C) $\frac { 1 } { \pi }$
(D) $\frac { 2 } { \pi }$
isi-entrance 2017 Q20 Average Value of a Function View
Let $f : [0,2] \rightarrow \mathbb{R}$ be a continuous function such that $$\frac{1}{2}\int_0^2 f(x)\,dx < f(2)$$ Then which of the following statements must be true?
(A) $f$ must be strictly increasing.
(B) $f$ must attain a maximum value at $x = 2$.
(C) $f$ cannot have a minimum at $x = 2$.
(D) None of the above.
isi-entrance 2020 Q5 Definite Integral as a Limit of Riemann Sums View
What is the limit of $\sum _ { k = 1 } ^ { n } \frac { e ^ { - k / n } } { n }$ as $n$ tends to $\infty$ ?
(A) The limit does not exist.
(B) $\infty$
(C) $1 - e ^ { - 1 }$
(D) $e ^ { - 0.5 }$
isi-entrance 2022 Q17 Convergence and Evaluation of Improper Integrals View
For $n \in \mathbb { N }$, let $a _ { n }$ be defined as $$a _ { n } = \int _ { 0 } ^ { n } \frac { 1 } { 1 + n x ^ { 2 } } d x$$ Then $\lim _ { n \rightarrow \infty } a _ { n }$
(A) equals 0
(B) equals $\frac { \pi } { 4 }$
(C) equals $\frac { \pi } { 2 }$
(D) does not exist
isi-entrance 2023 Q18 Integral Equation with Symmetry or Substitution View
Let $f : \mathbb { R } \rightarrow \mathbb { R }$ be a twice differentiable one-to-one function. If $f ( 2 ) = 2 , f ( 3 ) = - 8$ and $$\int _ { 2 } ^ { 3 } f ( x ) d x = - 3$$ then $$\int _ { - 8 } ^ { 2 } f ^ { - 1 } ( x ) d x$$ equals
(A) $- 25$.
(B) $25$.
(C) $- 31$.
(D) $31$.
isi-entrance 2026 Q1 Integral Equation with Symmetry or Substitution View
The value of the integral $\int _ { \pi / 2 } ^ { 5 \pi / 2 } \frac { e ^ { \tan ^ { - 1 } ( \sin x ) } } { e ^ { \tan ^ { - 1 } ( \sin x ) } + e ^ { \tan ^ { - 1 } ( \cos x ) } } d x$ equals
(a) 1 .
(B) $\pi$.
(C) $e$.
(D) none of these.
isi-entrance 2026 Q5 Definite Integral as a Limit of Riemann Sums View
If $a _ { n } = \left( 1 + \frac { 1 } { n ^ { 2 } } \right) \left( 1 + \frac { 2 ^ { 2 } } { n ^ { 2 } } \right) ^ { 2 } \left( 1 + \frac { 3 ^ { 2 } } { n ^ { 2 } } \right) ^ { 3 } \cdots \left( 1 + \frac { n ^ { 2 } } { n ^ { 2 } } \right) ^ { n }$, then $$\lim _ { n \rightarrow \infty } a _ { n } ^ { - 1 / n ^ { 2 } }$$ is
(a) 0 .
(B) 1 .
(C) $e$.
(D) $\sqrt { e } / 2$.
isi-entrance 2026 Q19 Maximizing or Optimizing a Definite Integral View
Suppose $a < b$. The maximum value of the integral $$\int _ { a } ^ { b } \left( \frac { 3 } { 4 } - x - x ^ { 2 } \right) d x$$ over all possible values of $a$ and $b$ is
(a) $3 / 4$.
(B) $4 / 3$.
(C) $3 / 2$.
(D) $2 / 3$.
jee-advanced 2007 Q66 Integral Inequalities and Limit of Integral Sequences View
Let $I = \int_0^1 \frac{\sin x}{\sqrt{x}}\,dx$ and $J = \int_0^1 \frac{\cos x}{\sqrt{x}}\,dx$. Then which one of the following is true?
(A) $I > \frac{2}{3}$ and $J > 2$
(B) $I < \frac{2}{3}$ and $J < 2$
(C) $I < \frac{2}{3}$ and $J > 2$
(D) $I > \frac{2}{3}$ and $J < 2$
jee-advanced 2007 Q68 Integral Equation with Symmetry or Substitution View
Match the statements in Column I with the values in Column II.
Column I
(A) $\int_{-\pi}^{\pi} \cos^2 x\,\frac{1}{1+a^x}\,dx$, $a > 0$
(B) $\int_0^{\pi/2} \frac{\sqrt{\sin x}}{\sqrt{\sin x}+\sqrt{\cos x}}\,dx$
(C) $\int_{-2}^{2} \frac{x^2}{1+5^x}\,dx$
(D) $\int_1^2 \frac{\sqrt{\ln(3-x)}}{\sqrt{\ln(3-x)}+\sqrt{\ln(x+1)}}\,dx$
Column II
(p) $\frac{1}{2}$
(q) $0$
(r) $\frac{\pi}{4}$
(s) $\frac{\pi}{2}$
jee-advanced 2008 Q10 Integral Equation with Symmetry or Substitution View
Let $f ( x )$ be a non-constant twice differentiable function defined on $( - \infty , \infty )$ such that $f ( x ) = f ( 1 - x )$ and $f ^ { \prime } \left( \frac { 1 } { 4 } \right) = 0$. Then,
(A) $f ^ { \prime \prime } ( x )$ vanishes at least twice on $[ 0,1 ]$
(B) $f ^ { \prime } \left( \frac { 1 } { 2 } \right) = 0$
(C) $\quad \int _ { - 1 / 2 } ^ { 1 / 2 } f \left( x + \frac { 1 } { 2 } \right) \sin x d x = 0$
(D) $\int _ { 0 } ^ { 1 / 2 } f ( t ) e ^ { \sin \pi t } d t = \int _ { 1 / 2 } ^ { 1 } f ( 1 - t ) e ^ { \sin \pi t } d t$
jee-advanced 2008 Q16 Accumulation Function Analysis View
Consider the function $f : ( - \infty , \infty ) \rightarrow ( - \infty , \infty )$ defined by
$$f ( x ) = \frac { x ^ { 2 } - a x + 1 } { x ^ { 2 } + a x + 1 } , 0 < a < 2 .$$
Let
$$g ( x ) = \int _ { 0 } ^ { e ^ { x } } \frac { f ^ { \prime } ( t ) } { 1 + t ^ { 2 } } d t$$
Which of the following is true?
(A) $g ^ { \prime } ( x )$ is positive on $( - \infty , 0 )$ and negative on $( 0 , \infty )$
(B) $g ^ { \prime } ( x )$ is negative on $( - \infty , 0 )$ and positive on $( 0 , \infty )$
(C) $g ^ { \prime } ( x )$ changes sign on both $( - \infty , 0 )$ and $( 0 , \infty )$
(D) $g ^ { \prime } ( x )$ does not change sign on $( - \infty , \infty )$
jee-advanced 2008 Q20 Recovering Function Values from Derivative Information View
Consider the functions defined implicitly by the equation $y ^ { 3 } - 3 y + x = 0$ on various intervals in the real line. If $x \in ( - \infty , - 2 ) \cup ( 2 , \infty )$, the equation implicitly defines a unique real valued differentiable function $y = f ( x )$. If $x \in ( - 2,2 )$, the equation implicitly defines a unique real valued differentiable function $y = g ( x )$ satisfying $g ( 0 ) = 0$.
$\int _ { - 1 } ^ { 1 } g ^ { \prime } ( x ) d x =$
(A) $2 g ( - 1 )$
(B) 0
(C) $- 2 g ( 1 )$
(D) $2 g ( 1 )$
jee-advanced 2009 Q24 Integral Equation with Symmetry or Substitution View
If $$I_{n}=\int_{-\pi}^{\pi}\frac{\sin nx}{\left(1+\pi^{x}\right)\sin x}dx,\quad n=0,1,2,\ldots,$$ then
(A) $I_{n}=I_{n+2}$
(B) $\sum_{m=1}^{10}I_{2m+1}=10\pi$
(C) $\sum_{m=1}^{10}I_{2m}=0$
(D) $I_{n}=I_{n+1}$
jee-advanced 2010 Q34 Accumulation Function Analysis View
The value of $\lim _ { x \rightarrow 0 } \frac { 1 } { x ^ { 3 } } \int _ { 0 } ^ { x } \frac { t \ln ( 1 + t ) } { t ^ { 4 } + 4 } d t$ is
A) 0
B) $\frac { 1 } { 12 }$
C) $\frac { 1 } { 24 }$
D) $\frac { 1 } { 64 }$
jee-advanced 2010 Q41 Definite Integral Evaluation (Computational) View
The value(s) of $\int _ { 0 } ^ { 1 } \frac { x ^ { 4 } ( 1 - x ) ^ { 4 } } { 1 + x ^ { 2 } } d x$ is (are)
A) $\frac { 22 } { 7 } - \pi$
B) $\frac { 2 } { 105 }$
C) 0
D) $\frac { 71 } { 15 } - \frac { 3 \pi } { 2 }$
jee-advanced 2010 Q52 Piecewise/Periodic Function Integration View
For any real number x, let $[ \mathrm { x } ]$ denote the largest integer less than or equal to x. Let $f$ be a real valued function defined on the interval $[ - 10,10 ]$ by $$f ( x ) = \left\{ \begin{array} { c c } x - [ x ] & \text { if } [ x ] \text { is odd } \\ 1 + [ x ] - x & \text { if } [ x ] \text { is even } \end{array} \right.$$ Then the value of $\frac { \pi ^ { 2 } } { 10 } \int _ { - 10 } ^ { 10 } f ( x ) \cos \pi x \, d x$ is
jee-advanced 2013 Q43 Integral Inequalities and Limit of Integral Sequences View
Let $f : \left[ \frac { 1 } { 2 } , 1 \right] \rightarrow \mathbb { R }$ (the set of all real numbers) be a positive, non-constant and differentiable function such that $f ^ { \prime } ( x ) < 2 f ( x )$ and $f \left( \frac { 1 } { 2 } \right) = 1$. Then the value of $\int _ { 1/2 } ^ { 1 } f ( x ) d x$ lies in the interval
(A) $( 2 e - 1,2 e )$
(B) $( e - 1,2 e - 1 )$
(C) $\left( \frac { e - 1 } { 2 } , e - 1 \right)$
(D) $\left( 0 , \frac { e - 1 } { 2 } \right)$
jee-advanced 2014 Q44 Finding a Function from an Integral Equation View
Let $f : [0,2] \rightarrow \mathbb{R}$ be a function which is continuous on $[0,2]$ and is differentiable on $(0,2)$ with $f(0) = 1$. Let
$$F(x) = \int_{0}^{x^2} f(\sqrt{t})\, dt$$
for $x \in [0,2]$. If $F'(x) = f'(x)$ for all $x \in (0,2)$, then $F(2)$ equals
(A) $e^2 - 1$
(B) $e^4 - 1$
(C) $e - 1$
(D) $e^4$
jee-advanced 2014 Q45 Properties of Integral-Defined Functions (Continuity, Differentiability) View
Let $f : [a,b] \rightarrow [1, \infty)$ be a continuous function and let $g : \mathbb{R} \rightarrow \mathbb{R}$ be defined as $$g(x) = \begin{cases} 0 & \text{if } x < a \\ \int_{a}^{x} f(t)\, dt & \text{if } a \leq x \leq b \\ \int_{a}^{b} f(t)\, dt & \text{if } x > b \end{cases}$$ Then
(A) $g(x)$ is continuous but not differentiable at $a$
(B) $g(x)$ is differentiable on $\mathbb{R}$
(C) $g(x)$ is continuous but not differentiable at $b$
(D) $g(x)$ is continuous and differentiable at either $a$ or $b$ but not both
jee-advanced 2014 Q58 Integral Equation with Symmetry or Substitution View
List IList II
P. The number of polynomials $f(x)$ with non-negative integer coefficients of degree $\leq 2$, satisfying $f(0) = 0$ and $\int_{0}^{1} f(x)\,dx = 1$, is1. 8
Q. The number of points in the interval $[-\sqrt{13}, \sqrt{13}]$ at which $f(x) = \sin(x^2) + \cos(x^2)$ attains its maximum value, is2. 2
R. $\int_{-2}^{2} \frac{3x^2}{1+e^x}\,dx$ equals3. 4
S. $\dfrac{\displaystyle\int_{-\frac{1}{2}}^{\frac{1}{2}} \cos 2x \log\left(\frac{1+x}{1-x}\right)dx}{\displaystyle\int_{0}^{\frac{1}{2}} \cos 2x \log\left(\frac{1+x}{1-x}\right)dx}$ equals4. 0

P Q R S
(A) 3241
(B) 2341
(C) 3214
(D) 2314
jee-advanced 2015 Q46 Piecewise/Periodic Function Integration View
Let $f : \mathbb { R } \rightarrow \mathbb { R }$ be a function defined by $f ( x ) = \left\{ \begin{array} { l l } { [ x ] , } & x \leq 2 \\ 0 , & x > 2 \end{array} \right.$, where $[ x ]$ is the greatest integer less than or equal to $x$. If $I = \int _ { - 1 } ^ { 2 } \frac { x f \left( x ^ { 2 } \right) } { 2 + f ( x + 1 ) } d x$, then the value of $( 4 I - 1 )$ is
jee-advanced 2015 Q47 Finding a Function from an Integral Equation View
Let $f : \mathbb { R } \rightarrow \mathbb { R }$ be a continuous odd function, which vanishes exactly at one point and $f ( 1 ) = \frac { 1 } { 2 }$. Suppose that $F ( x ) = \int _ { - 1 } ^ { x } f ( t ) d t$ for all $x \in [ - 1,2 ]$ and $G ( x ) = \int _ { - 1 } ^ { x } t | f ( f ( t ) ) | d t$ for all $x \in [ - 1,2 ]$. If $\lim _ { x \rightarrow 1 } \frac { F ( x ) } { G ( x ) } = \frac { 1 } { 14 }$, then the value of $f \left( \frac { 1 } { 2 } \right)$ is
jee-advanced 2015 Q48 Finding a Function from an Integral Equation View
Let $F ( x ) = \int _ { x } ^ { x ^ { 2 } + \frac { \pi } { 6 } } 2 \cos ^ { 2 } t \, d t$ for all $x \in \mathbb { R }$ and $f : \left[ 0 , \frac { 1 } { 2 } \right] \rightarrow [ 0 , \infty )$ be a continuous function. For $a \in \left[ 0 , \frac { 1 } { 2 } \right]$, if $F ^ { \prime } ( a ) + 2$ is the area of the region bounded by $x = 0 , y = 0 , y = f ( x )$ and $x = a$, then $f ( 0 )$ is