Functions

41 Questions Numerical
2025 JEE Mains Numerical
JEE Main 2025 (Online) 8th April Evening Shift

Let the domain of the function $f(x)=\cos ^{-1}\left(\frac{4 x+5}{3 x-7}\right)$ be $[\alpha, \beta]$ and the domain of $g(x)=\log _2\left(2-6 \log _{27}(2 x+5)\right)$ be $(\gamma, \delta)$.

Then $|7(\alpha+\beta)+4(\gamma+\delta)|$ is equal to ______________.

2024 JEE Mains Numerical
JEE Main 2024 (Online) 9th April Evening Shift

Let $A=\{(x, y): 2 x+3 y=23, x, y \in \mathbb{N}\}$ and $B=\{x:(x, y) \in A\}$. Then the number of one-one functions from $A$ to $B$ is equal to _________.

2024 JEE Mains Numerical
JEE Main 2024 (Online) 9th April Morning Shift

If a function $f$ satisfies $f(\mathrm{~m}+\mathrm{n})=f(\mathrm{~m})+f(\mathrm{n})$ for all $\mathrm{m}, \mathrm{n} \in \mathbf{N}$ and $f(1)=1$, then the largest natural number $\lambda$ such that $\sum_\limits{\mathrm{k}=1}^{2022} f(\lambda+\mathrm{k}) \leq(2022)^2$ is equal to _________.

2024 JEE Mains Numerical
JEE Main 2024 (Online) 8th April Morning Shift

If the range of $f(\theta)=\frac{\sin ^4 \theta+3 \cos ^2 \theta}{\sin ^4 \theta+\cos ^2 \theta}, \theta \in \mathbb{R}$ is $[\alpha, \beta]$, then the sum of the infinite G.P., whose first term is 64 and the common ratio is $\frac{\alpha}{\beta}$, is equal to __________.

2024 JEE Mains Numerical
JEE Main 2024 (Online) 5th April Morning Shift

If $S=\{a \in \mathbf{R}:|2 a-1|=3[a]+2\{a \}\}$, where $[t]$ denotes the greatest integer less than or equal to $t$ and $\{t\}$ represents the fractional part of $t$, then $72 \sum_\limits{a \in S} a$ is equal to _________.

2024 JEE Mains Numerical
JEE Main 2024 (Online) 4th April Evening Shift

Consider the function $f: \mathbb{R} \rightarrow \mathbb{R}$ defined by $f(x)=\frac{2 x}{\sqrt{1+9 x^2}}$. If the composition of $f, \underbrace{(f \circ f \circ f \circ \cdots \circ f)}_{10 \text { times }}(x)=\frac{2^{10} x}{\sqrt{1+9 \alpha x^2}}$, then the value of $\sqrt{3 \alpha+1}$ is equal to _______.

2024 JEE Mains Numerical
JEE Main 2024 (Online) 30th January Morning Shift

Let $\mathrm{A}=\{1,2,3, \ldots, 7\}$ and let $\mathrm{P}(\mathrm{A})$ denote the power set of $\mathrm{A}$. If the number of functions $f: \mathrm{A} \rightarrow \mathrm{P}(\mathrm{A})$ such that $\mathrm{a} \in f(\mathrm{a}), \forall \mathrm{a} \in \mathrm{A}$ is $\mathrm{m}^{\mathrm{n}}, \mathrm{m}$ and $\mathrm{n} \in \mathrm{N}$ and $\mathrm{m}$ is least, then $\mathrm{m}+\mathrm{n}$ is equal to _________.

2023 JEE Mains Numerical
JEE Main 2023 (Online) 11th April Evening Shift

Let $\mathrm{A}=\{1,2,3,4,5\}$ and $\mathrm{B}=\{1,2,3,4,5,6\}$. Then the number of functions $f: \mathrm{A} \rightarrow \mathrm{B}$ satisfying $f(1)+f(2)=f(4)-1$ is equal to __________.

2023 JEE Mains Numerical
JEE Main 2023 (Online) 8th April Evening Shift

Let $\mathrm{R}=\{\mathrm{a}, \mathrm{b}, \mathrm{c}, \mathrm{d}, \mathrm{e}\}$ and $\mathrm{S}=\{1,2,3,4\}$. Total number of onto functions $f: \mathrm{R} \rightarrow \mathrm{S}$ such that $f(\mathrm{a}) \neq 1$, is equal to ______________.

2023 JEE Mains Numerical
JEE Main 2023 (Online) 8th April Evening Shift

If domain of the function $\log _{e}\left(\frac{6 x^{2}+5 x+1}{2 x-1}\right)+\cos ^{-1}\left(\frac{2 x^{2}-3 x+4}{3 x-5}\right)$ is $(\alpha, \beta) \cup(\gamma, \delta]$, then $18\left(\alpha^{2}+\beta^{2}+\gamma^{2}+\delta^{2}\right)$ is equal to ______________.

2023 JEE Mains Numerical
JEE Main 2023 (Online) 30th January Evening Shift
Let $A=\{1,2,3,5,8,9\}$. Then the number of possible functions $f: A \rightarrow A$ such that $f(m \cdot n)=f(m) \cdot f(n)$ for every $m, n \in A$ with $m \cdot n \in A$ is equal to ___________.
2023 JEE Mains Numerical
JEE Main 2023 (Online) 30th January Morning Shift

Let $S=\{1,2,3,4,5,6\}$. Then the number of one-one functions $f: \mathrm{S} \rightarrow \mathrm{P}(\mathrm{S})$, where $\mathrm{P}(\mathrm{S})$ denote the power set of $\mathrm{S}$, such that $f(n) \subset f(\mathrm{~m})$ where $n < m$ is ____________.

2023 JEE Mains Numerical
JEE Main 2023 (Online) 29th January Morning Shift

Suppose $f$ is a function satisfying $f(x + y) = f(x) + f(y)$ for all $x,y \in N$ and $f(1) = {1 \over 5}$. If $\sum\limits_{n = 1}^m {{{f(n)} \over {n(n + 1)(n + 2)}} = {1 \over {12}}} $, then $m$ is equal to __________.

2023 JEE Mains Numerical
JEE Main 2023 (Online) 25th January Morning Shift

For some a, b, c $\in\mathbb{N}$, let $f(x) = ax - 3$ and $\mathrm{g(x)=x^b+c,x\in\mathbb{R}}$. If ${(fog)^{ - 1}}(x) = {\left( {{{x - 7} \over 2}} \right)^{1/3}}$, then $(fog)(ac) + (gof)(b)$ is equal to ____________.

2022 JEE Mains Numerical
JEE Main 2022 (Online) 28th July Morning Shift

For $\mathrm{p}, \mathrm{q} \in \mathbf{R}$, consider the real valued function $f(x)=(x-\mathrm{p})^{2}-\mathrm{q}, x \in \mathbf{R}$ and $\mathrm{q}>0$. Let $\mathrm{a}_{1}$, $\mathrm{a}_{2^{\prime}}$ $\mathrm{a}_{3}$ and $\mathrm{a}_{4}$ be in an arithmetic progression with mean $\mathrm{p}$ and positive common difference. If $\left|f\left(\mathrm{a}_{i}\right)\right|=500$ for all $i=1,2,3,4$, then the absolute difference between the roots of $f(x)=0$ is ___________.

2022 JEE Mains Numerical
JEE Main 2022 (Online) 27th July Evening Shift

The number of functions $f$, from the set $\mathrm{A}=\left\{x \in \mathbf{N}: x^{2}-10 x+9 \leq 0\right\}$ to the set $\mathrm{B}=\left\{\mathrm{n}^{2}: \mathrm{n} \in \mathbf{N}\right\}$ such that $f(x) \leq(x-3)^{2}+1$, for every $x \in \mathrm{A}$, is ___________.

2022 JEE Mains Numerical
JEE Main 2022 (Online) 27th July Morning Shift

Let $f(x)=2 x^{2}-x-1$ and $\mathrm{S}=\{n \in \mathbb{Z}:|f(n)| \leq 800\}$. Then, the value of $\sum\limits_{n \in S} f(n)$ is equal to ___________.

2022 JEE Mains Numerical
JEE Main 2022 (Online) 25th July Evening Shift

Let $f(x)$ be a quadratic polynomial with leading coefficient 1 such that $f(0)=p, p \neq 0$, and $f(1)=\frac{1}{3}$. If the equations $f(x)=0$ and $f \circ f \circ f \circ f(x)=0$ have a common real root, then $f(-3)$ is equal to ________________.

2022 JEE Mains Numerical
JEE Main 2022 (Online) 29th June Evening Shift

Let f(x) and g(x) be two real polynomials of degree 2 and 1 respectively. If $f(g(x)) = 8{x^2} - 2x$ and $g(f(x)) = 4{x^2} + 6x + 1$, then the value of $f(2) + g(2)$ is _________.

2022 JEE Mains Numerical
JEE Main 2022 (Online) 29th June Morning Shift

Let c, k $\in$ R. If $f(x) = (c + 1){x^2} + (1 - {c^2})x + 2k$ and $f(x + y) = f(x) + f(y) - xy$, for all x, y $\in$ R, then the value of $|2(f(1) + f(2) + f(3) + \,\,......\,\, + \,\,f(20))|$ is equal to ____________.

2022 JEE Mains Numerical
JEE Main 2022 (Online) 28th June Evening Shift

Let S = {1, 2, 3, 4}. Then the number of elements in the set { f : S $\times$ S $\to$ S : f is onto and f (a, b) = f (b, a) $\ge$ a $\forall$ (a, b) $\in$ S $\times$ S } is ______________.

2022 JEE Mains Numerical
JEE Main 2022 (Online) 27th June Evening Shift

Let S = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}. Define f : S $\to$ S as

$f(n) = \left\{ {\matrix{ {2n} & , & {if\,n = 1,2,3,4,5} \cr {2n - 11} & , & {if\,n = 6,7,8,9,10} \cr } } \right.$.

Let g : S $\to$ S be a function such that $fog(n) = \left\{ {\matrix{ {n + 1} & , & {if\,n\,\,is\,odd} \cr {n - 1} & , & {if\,n\,\,is\,even} \cr } } \right.$.

Then $g(10)g(1) + g(2) + g(3) + g(4) + g(5))$ is equal to _____________.

2022 JEE Mains Numerical
JEE Main 2022 (Online) 27th June Morning Shift

Let f : R $\to$ R be a function defined by $f(x) = {{2{e^{2x}}} \over {{e^{2x}} + e}}$. Then $f\left( {{1 \over {100}}} \right) + f\left( {{2 \over {100}}} \right) + f\left( {{3 \over {100}}} \right) + \,\,\,.....\,\,\, + \,\,\,f\left( {{{99} \over {100}}} \right)$ is equal to ______________.

2022 JEE Mains Numerical
JEE Main 2022 (Online) 25th June Morning Shift

Let $f:R \to R$ be a function defined by

$f(x) = {\left( {2\left( {1 - {{{x^{25}}} \over 2}} \right)(2 + {x^{25}})} \right)^{{1 \over {50}}}}$. If the function $g(x) = f(f(f(x))) + f(f(x))$, then the greatest integer less than or equal to g(1) is ____________.

2022 JEE Mains Numerical
JEE Main 2022 (Online) 24th June Morning Shift

The number of one-one functions f : {a, b, c, d} $\to$ {0, 1, 2, ......, 10} such

that 2f(a) $-$ f(b) + 3f(c) + f(d) = 0 is ___________.

2021 JEE Mains Numerical
JEE Main 2021 (Online) 27th July Morning Shift
Let S = {1, 2, 3, 4, 5, 6, 7}. Then the number of possible functions f : S $\to$ S
such that f(m . n) = f(m) . f(n) for every m, n $\in$ S and m . n $\in$ S is equal to _____________.
2021 JEE Mains Numerical
JEE Main 2021 (Online) 22th July Evening Shift
Let A = {0, 1, 2, 3, 4, 5, 6, 7}. Then the number of bijective functions f : A $\to$ A such that f(1) + f(2) = 3 $-$ f(3) is equal to
2021 JEE Mains Numerical
JEE Main 2021 (Online) 18th March Evening Shift
If f(x) and g(x) are two polynomials such that the polynomial P(x) = f(x3) + x g(x3) is divisible by x2 + x + 1, then P(1) is equal to ___________.
2021 JEE Mains Numerical
JEE Main 2021 (Online) 24th February Evening Shift
If a + $\alpha$ = 1, b + $\beta$ = 2 and $af(x) + \alpha f\left( {{1 \over x}} \right) = bx + {\beta \over x},x \ne 0$, then the value of the expression ${{f(x) + f\left( {{1 \over x}} \right)} \over {x + {1 \over x}}}$ is __________.
2020 JEE Mains Numerical
JEE Main 2020 (Online) 6th September Evening Slot
Suppose that a function f : R $ \to $ R satisfies
f(x + y) = f(x)f(y) for all x, y $ \in $ R and f(1) = 3.
If $\sum\limits_{i = 1}^n {f(i)} = 363$ then n is equal to ________ .
2020 JEE Mains Numerical
JEE Main 2020 (Online) 5th September Evening Slot
Let A = {a, b, c} and B = {1, 2, 3, 4}. Then the number of elements in the set
C = {f : A $ \to $ B | 2 $ \in $ f(A) and f is not one-one} is ______.
2025 JEE Advanced Numerical
JEE Advanced 2025 Paper 2 Online

Let $\mathbb{R}$ denote the set of all real numbers. Let $f: \mathbb{R} \rightarrow \mathbb{R}$ and $g: \mathbb{R} \rightarrow(0,4)$ be functions defined by

$ f(x)=\log _e\left(x^2+2 x+4\right), \text { and } g(x)=\frac{4}{1+e^{-2 x}} $

Define the composite function $f \circ g^{-1}$ by $\left(f \circ g^{-1}\right)(x)=f\left(g^{-1}(x)\right)$, where $g^{-1}$ is the inverse of the function $g$.

Then the value of the derivative of the composite function $f \circ g^{-1}$ at $x=2$ is ________________.

2025 JEE Advanced Numerical
JEE Advanced 2025 Paper 1 Online

Let denote the set of all real numbers. Let f: ℝ → ℝ be a function such that f(x) > 0 for all x ∈ ℝ, and f(x+y) = f(x)f(y) for all x, y ∈ ℝ.

Let the real numbers a₁, a₂, ..., a₅₀ be in an arithmetic progression. If f(a₃₁) = 64f(a₂₅), and

$ \sum\limits_{i=1}^{50} f(a_i) = 3(2^{25}+1), $

then the value of

$ \sum\limits_{i=6}^{30} f(a_i) $

is ________________.

2024 JEE Advanced Numerical
JEE Advanced 2024 Paper 2 Online
Let $f: \mathbb{R} \rightarrow \mathbb{R}$ be a function such that $f(x+y)=f(x)+f(y)$ for all $x, y \in \mathbb{R}$, and $g: \mathbb{R} \rightarrow(0, \infty)$ be a function such that $g(x+y)=g(x) g(y)$ for all $x, y \in \mathbb{R}$. If $f\left(\frac{-3}{5}\right)=12$ and $g\left(\frac{-1}{3}\right)=2$, then the value of $\left(f\left(\frac{1}{4}\right)+g(-2)-8\right) g(0)$ is _________.
2024 JEE Advanced Numerical
JEE Advanced 2024 Paper 2 Online

Let the function $f: \mathbb{R} \rightarrow \mathbb{R}$ be defined by

$ f(x)=\frac{\sin x}{e^{\pi x}} \frac{\left(x^{2023}+2024 x+2025\right)}{\left(x^2-x+3\right)}+\frac{2}{e^{\pi x}} \frac{\left(x^{2023}+2024 x+2025\right)}{\left(x^2-x+3\right)} . $

Then the number of solutions of $f(x)=0$ in $\mathbb{R}$ is _________.

2020 JEE Advanced Numerical
JEE Advanced 2020 Paper 2 Offline
Let the function f : [0, 1] $ \to $ R be defined by

$f(x) = {{{4^x}} \over {{4^x} + 2}}$

Then the value of $f\left( {{1 \over {40}}} \right) + f\left( {{2 \over {40}}} \right) + f\left( {{3 \over {40}}} \right) + ... + f\left( {{{39} \over {40}}} \right) - f\left( {{1 \over 2}} \right)$ is ..........
2020 JEE Advanced Numerical
JEE Advanced 2020 Paper 2 Offline
Let the function $f:(0,\pi ) \to R$ be defined by $f(\theta ) = {(\sin \theta + \cos \theta )^2} + {(\sin \theta - \cos \theta )^4}$

Suppose the function f has a local minimum at $\theta $ precisely when $\theta \in \{ {\lambda _1}\pi ,....,{\lambda _r}\pi \} $, where $0 < {\lambda _1} < ...{\lambda _r} < 1$. Then the value of ${\lambda _1} + ... + {\lambda _r}$ is .............
2020 JEE Advanced Numerical
JEE Advanced 2020 Paper 1 Offline
Let f : [0, 2] $ \to $ R be the function defined by

$f(x) = (3 - \sin (2\pi x))\sin \left( {\pi x - {\pi \over 4}} \right) - \sin \left( {3\pi x + {\pi \over 4}} \right)$

If $\alpha ,\,\beta \in [0,2]$ are such that $\{ x \in [0,2]:f(x) \ge 0\} = [\alpha ,\beta ]$, then the value of $\beta - \alpha $ is ..........
2020 JEE Advanced Numerical
JEE Advanced 2020 Paper 1 Offline
For a polynomial g(x) with real coefficients, let mg denote the number of distinct real roots of g(x). Suppose S is the set of polynomials with real coefficients defined by

$S = \{ {({x^2} - 1)^2}({a_0} + {a_1}x + {a_2}{x^2} + {a_3}{x^3}):{a_0},{a_1},{a_2},{a_3} \in R\} $;

For a polynomial f, let f' and f'' denote its first and second order derivatives, respectively. Then the minimum possible value of (mf' + mf''), where f $ \in $ S, is ..............
2018 JEE Advanced Numerical
JEE Advanced 2018 Paper 2 Offline
Let X be a set with exactly 5 elements and Y be a set with exactly 7 elements. If $\alpha $ is the number of one-one functions from X to Y and $\beta $ is the number of onto functions from Y to X, then the value of ${1 \over {5!}}(\beta - \alpha )$ is ..................
2009 JEE Advanced Numerical
IIT-JEE 2009 Paper 2 Offline

If the function $f(x) = {x^3} + {e^{x/2}}$ and $g(x) = {f^{ - 1}}(x)$, then the value of $g'(1)$ is _________.