If the range of the function $f(x)=-3 x-3$ is $\{3,-6,-9,-18\}$, then which one of the following is not in the domain of $f$ ?
-1
-2
2
5
$\{7,8,9\}$
$\{4,5,6\}$
$\{5,6,7\}$
$\{6,7,8\}$
If $f(x)=(x+1)^2-1, x \geq-1$, then $\left\{x \mid f(x)=f^{-1}(x)\right\}$ is
$\{0,-1\}$
$\{-1,0,1\}$
$\left\{-1,0, \frac{-3+\sqrt{3} i}{2}, \frac{-3-\sqrt{3} i}{2}\right\}$
an empty set
$ \text { Consider the following statements. } $
$ \begin{array}{cl} \hline \text { Statement I } & \begin{array}{l} \text { A function } f: A \rightarrow B \text { is said to be one-one if and } \\ \text { only if } f(x) \neq f(y) \Rightarrow x \neq y \end{array} \\ \hline \text { Statement II } & \begin{array}{l} \text { A relation } f: A \rightarrow B \text { is said to be a function if } x \neq y \\ \Rightarrow f(x) \neq f(y) \end{array} \\ \hline \end{array} $
Then, which one of the following is true?
Only statement I is true.
Only statement II is true.
Both Statement I and Statement II are true.
Neither Statement I nor Statement II is true.
The set of all real values of $x$ for which $f(x)=\sqrt{\frac{|x|-2}{|x|-3}}$ is a well defined function is
$(-3,-2] \cup(2,3]$
$R-[-3,-2) \cup(2,3]$
$R-[-3,3]$
$(-3,3)$
Let $f: N \rightarrow N$ be a function such that $f(x+y)=f(x)+f(y)+x y$ for every $x, y \in N$. If $f(\mathbb{l})=2$, then $\sum_{k=0}^{10} f(k)=$
1650
275
550
1025
If a real valued function $f:[-1,2] \rightarrow B$ defined by
$ f(x)= \begin{cases}1-x, & \text { when }-1 \leq x \leq 1 \\ x-1, & \text { when } 1 < x \leq 2\end{cases} $
is a surjection, then $B=$
$[-1,2]$
$[-1,1]$
$[0,2]$
$[0,1]$
The sum of the least positive integer and the greatest negative integer in the range of the function $f(x)=\frac{x^2-5 x+7}{x^2-5 x-7}$ is
0
1
2
-1
The interval in which the curve represented by $f(x)=2 x+\log \left(\frac{x}{2+x}\right)$ is
$(-\infty, 0)$
$(-2, \infty)$
$(-\infty,-2) \cup(0, \infty)$
$(-2,0)$
The set of real values of $x$ such that $f(x)=\sqrt{\frac{[x]-1}{\left.[x]^2-[x]-6\right]}}$ is a real valued function is
$[1, \infty)$
$(-\infty,-2) \cup[4, \infty)$
$[-1,3)$
$[-1,2) \cup[4, \infty)$
If a function $f: Z \rightarrow Z$ is defined by $f(x)=x-(-1)^x$, then $f(x)$ is
one-one, but not onto
onto but not one-one
both one-one and onto
neither one-one nor onto
Domain of the real valued function $f(x)=\log \left(x^2-1\right)+x \operatorname{coth}^{-1} x$ is
$R$
$(-1,1)$
$R-[-1,1]$
$R-[0,1]$
The domain and range of a real valued function $f(x)=\cos x-3$ are respectively
$R \backslash\{0\}$ and $[-1,1]$
$R$ and $[-1,1]$
$R \backslash\{0\}$ and $[-4,-2]$
$R$ and $[-4,-2]$
If $f: R \rightarrow R$ and $g: R \rightarrow R$ are two functions defined by $f(x)=2 x-3$ and $g(x)=5 x^2-2$, then the least value of the function $(g \circ f)(x)$ is
-2
2
-4
4
Let the range of the function $f(x)=\frac{1}{2+\sin 3 x+\cos 3 x}, x \in \mathbb{R}$ be $[a, b]$. If $\alpha$ and $\beta$ ar respectively the A.M. and the G.M. of $a$ and $b$, then $\frac{\alpha}{\beta}$ is equal to
If the domain of the function $f(x)=\sin ^{-1}\left(\frac{x-1}{2 x+3}\right)$ is $\mathbf{R}-(\alpha, \beta)$, then $12 \alpha \beta$ is equal to :
Let $f(x)=\left\{\begin{array}{ccc}-\mathrm{a} & \text { if } & -\mathrm{a} \leq x \leq 0 \\ x+\mathrm{a} & \text { if } & 0< x \leq \mathrm{a}\end{array}\right.$ where $\mathrm{a}> 0$ and $\mathrm{g}(x)=(f(|x|)-|f(x)|) / 2$. Then the function $g:[-a, a] \rightarrow[-a, a]$ is
If the function $f(x)=\left(\frac{1}{x}\right)^{2 x} ; x>0$ attains the maximum value at $x=\frac{1}{\mathrm{e}}$ then :
Let $f(x)=\frac{1}{7-\sin 5 x}$ be a function defined on $\mathbf{R}$. Then the range of the function $f(x)$ is equal to :
The function $f(x)=\frac{x^2+2 x-15}{x^2-4 x+9}, x \in \mathbb{R}$ is
Let $f, g: \mathbf{R} \rightarrow \mathbf{R}$ be defined as :
$f(x)=|x-1| \text { and } g(x)= \begin{cases}\mathrm{e}^x, & x \geq 0 \\ x+1, & x \leq 0 .\end{cases}$
Then the function $f(g(x))$ is
Let $A=\{1,3,7,9,11\}$ and $B=\{2,4,5,7,8,10,12\}$. Then the total number of one-one maps $f: A \rightarrow B$, such that $f(1)+f(3)=14$, is :
$f(x)=\frac{\sqrt{x^2-25}}{\left(4-x^2\right)}+\log _{10}\left(x^2+2 x-15\right)$ is $(-\infty, \alpha) \cup[\beta, \infty)$, then $\alpha^2+\beta^3$ is equal to :
$f(x)=\left\{\begin{array}{ll}\log _{\mathrm{e}} x, & x>0 \\ \mathrm{e}^{-x}, & x \leq 0\end{array}\right.$ and
$g(x)=\left\{\begin{array}{ll}x, & x \geqslant 0 \\ \mathrm{e}^x, & x<0\end{array}\right.$. Then, gof : $\mathbf{R} \rightarrow \mathbf{R}$ is :
If $f(x)=\frac{4 x+3}{6 x-4}, x \neq \frac{2}{3}$ and $(f \circ f)(x)=g(x)$, where $g: \mathbb{R}-\left\{\frac{2}{3}\right\} \rightarrow \mathbb{R}-\left\{\frac{2}{3}\right\}$, then $(g ogog)(4)$ is equal to
If the domain of the function $f(x)=\log _e\left(\frac{2 x+3}{4 x^2+x-3}\right)+\cos ^{-1}\left(\frac{2 x-1}{x+2}\right)$ is $(\alpha, \beta]$, then the value of $5 \beta-4 \alpha$ is equal to
If the domain of the function $f(x)=\cos ^{-1}\left(\frac{2-|x|}{4}\right)+\left\{\log _e(3-x)\right\}^{-1}$ is $[-\alpha, \beta)-\{\gamma\}$, then $\alpha+\beta+\gamma$ is equal to :
If $f(x)=\left\{\begin{array}{cc}2+2 x, & -1 \leq x < 0 \\ 1-\frac{x}{3}, & 0 \leq x \leq 3\end{array} ; g(x)=\left\{\begin{array}{cc}-x, & -3 \leq x \leq 0 \\ x, & 0 < x \leq 1\end{array}\right.\right.$, then range of $(f o g)(x)$ is
Let $f: \mathbf{R}-\left\{\frac{-1}{2}\right\} \rightarrow \mathbf{R}$ and $g: \mathbf{R}-\left\{\frac{-5}{2}\right\} \rightarrow \mathbf{R}$ be defined as $f(x)=\frac{2 x+3}{2 x+1}$ and $g(x)=\frac{|x|+1}{2 x+5}$. Then, the domain of the function fog is :
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 _________.
Explanation:
$\begin{aligned} & A=\{(x, y) ; 2 x+3 y=23, x, y \in N\} \\ & A=\{(1,7),(4,5),(7,3),(10,1)\} \\ & B=\{x:(x, y) \in A\} \\ & B=\{1,4,7,10\} \end{aligned}$
So, total number of one-one functions from A to B is $4!=24$
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 _________.
Explanation:
$\begin{aligned} & f(m+n)=f(m)+f(n) \\ & f(x)=k x \\ & \because f(1)=1 \\ & \Rightarrow k=1 \\ & \Rightarrow f(x)=x \end{aligned}$
$\begin{aligned} & \sum_{k=1}^{2022} f(\lambda+k)=\sum_{k=1}^{2022}(\lambda+k)=\underbrace{\lambda+\lambda+\ldots+\lambda}_{2022}+(1+2+\ldots+2022) \\ & =2022 \lambda+\frac{2022 \times 2023}{2} \leq(2022)^2 \\ & \Rightarrow \lambda \leq \frac{2021}{2} \\ & \text { largest } \lambda=1010 \end{aligned}$
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 __________.
Explanation:
To determine the range of the function $f(\theta)=\frac{\sin ^4 \theta+3 \cos ^2 \theta}{\sin ^4 \theta+\cos ^2 \theta}$, let's start by simplifying the expression. Let $\sin^2 \theta = x$, so $\cos^2 \theta = 1 - x$. The function then transforms into:
$ f(x) = \frac{x^2 + 3(1-x)}{x^2 + (1-x)} $
Simplify the numerator and denominator separately:
Numerator: $ x^2 + 3 - 3x $
Denominator: $ x^2 + 1 - x $
Thus, the function becomes:
$ f(x) = \frac{x^2 + 3 - 3x}{x^2 + 1 - x} = \frac{x^2 - 3x + 3}{x^2 - x + 1} $
Next, we need to find the range of this function. Let's analyze the function by testing specific values of $x$ in the interval $[0, 1]$ (since $\sin^2 \theta$ ranges from 0 to 1):
When $x = 0$:
$ f(0) = \frac{0^2 - 3(0) + 3}{0^2 - 0 + 1} = \frac{3}{1} = 3 $
When $x = 1$:
$ f(1) = \frac{1^2 - 3(1) + 3}{1^2 - 1 + 1} = \frac{1 - 3 + 3}{1 - 1 + 1} = \frac{1}{1} = 1 $
It appears that $f(x)$ achieves values within $[1, 3]$. To confirm this, we need to solve the quadratic inequality:
$ 1 \leq \frac{x^2 - 3x + 3}{x^2 - x + 1} \leq 3 $
By solving the inequalities, it can be confirmed that the function indeed ranges from 1 to 3 on the interval [0,1]. Hence, we have:
$ \alpha = 1 $
$ \beta = 3 $
The common ratio of the infinite geometric progression is:
$ \frac{\alpha}{\beta} = \frac{1}{3} $
Given the first term $a = 64$, the sum $S$ of the infinite geometric progression can be given as:
$ S = \frac{a}{1 - r} $
Substituting the values $a = 64$ and $r = \frac{1}{3}$, we get:
$ S = \frac{64}{1 - \frac{1}{3}} = \frac{64}{\frac{2}{3}} = 64 \times \frac{3}{2} = 96 $
Therefore, the sum of the infinite geometric progression is 96.
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 _________.
Explanation:
$\begin{aligned} & S:\{a \in R:|2 a-1|=3[a]+2\{a\}\} \\ & |2 a-1|=3[a]+2(a-[a]) \\ & |2 a-1|=[a]+2 a \end{aligned}$
Case I: If $0 < a < \frac{1}{2}$
$\begin{aligned} & 1-2 a=0+2 a \\ & \Rightarrow a=\frac{1}{4} \end{aligned}$
Case II: If $\frac{1}{2} < a < 1$
$2 a-1=0+2 a$
No solution
Case III: If $1 \leq a<2$
$2 a-1=1+2 a$
$\Rightarrow$ No solution
$\therefore$ only solution is $a=\frac{1}{4}$
$72 \sum_\limits{a \in S} a=72 \times \frac{1}{4}=18$
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 _______.
Explanation:
$f(x)=\frac{2 x}{\sqrt{1+9 x^2}}$
$(f \circ f)(x)=\frac{2 f(x)}{\sqrt{1+9(f(x))^2}}=\frac{\frac{4 x}{\sqrt{1+9 x^2}}}{\sqrt{1+9 \times \frac{4 x^2}{1+9 x^2}}}=\frac{4 x}{\sqrt{1+45 x^2}}$
$(f \circ f \circ f)(x)=\frac{4 \times \frac{2 x}{\sqrt{1+9 x^2}}}{\sqrt{1+45 \times \frac{4 x^2}{1+9 x^2}}}=\frac{8 x}{\sqrt{1+21 \times 9 x^2}}$
$(f \circ f \circ f \circ f)(x)=\frac{16 x}{\sqrt{1+85 \times 9 x^2}}$
$\Rightarrow \alpha$ is $10^{\text {th }}$ term of $1,5,21,85, \ldots \alpha$ is $10^{\text {th }}$ term of
$\begin{aligned} & \frac{\left(2^1\right)^2-1}{3}, \frac{\left(2^2\right)^2-1}{3}, \frac{\left(2^3\right)^2-1}{3}, \frac{\left(2^4\right)^2-1}{3}, \ldots \\ \Rightarrow \quad & \alpha=\frac{\left(2^{10}\right)^2-1}{3} \\ \Rightarrow \quad & \sqrt{3 \alpha+1}=2^{10}=1024 \end{aligned}$
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 _________.
Explanation:
$\begin{aligned} & f: A \rightarrow P(A) \\ & a \in f(a) \end{aligned}$
That means '$a$' will connect with subset which contain element '$a$'.
Total options for 1 will be $2^6$. (Because $2^6$ subsets contains 1)
Similarly, for every other element
Hence, total is $2^6 \times 2^6 \times 2^6 \times 2^6 \times 2^6 \times 2^6 \times 2^6=2^{42}$
Ans. $2+42=44$
Explanation:
$\begin{aligned} & \mathrm{f}(\mathrm{x}+\mathrm{y})=\mathrm{f}(\mathrm{x})+\mathrm{f}(\mathrm{y}) \quad \text{... (1)}\\ & \Rightarrow \quad \mathrm{f}(\mathrm{nx})=\operatorname{nf}(\mathrm{x}) \forall \mathrm{n} \in \mathrm{N} \quad \text{... (2)} \end{aligned}$
$ \begin{array}{ll} \text { Now } & \text { put } \mathrm{y}=-\mathrm{x} \text { in eq.(1) } \\ & \mathrm{f}(\mathrm{x})+\mathrm{f}(-\mathrm{x})=\mathrm{f}(0) \quad\{\mathrm{f}(0)=0\} \\ \Rightarrow \quad & \mathrm{f}(-\mathrm{x})=-\mathrm{f}(\mathrm{x}) \\ \Rightarrow \quad & \mathrm{f} \text { is odd function } \\ & \text { from eq. (2) } \\ & \mathrm{f}(-\mathrm{nx})=\mathrm{nf}(-\mathrm{x}) \\ \Rightarrow \quad & \mathrm{f}(-\mathrm{nx})=-\mathrm{nf}(\mathrm{x}) \\ \Rightarrow \quad & \mathrm{f}(\mathrm{mx})=\operatorname{mf}(\mathrm{x}) \forall \mathrm{m} \in \mathrm{Z}^{-} \quad \text{... (3)}\\ & \text {from eq. (2) and eq. (3) } \\ & \mathrm{f}(\mathrm{nx})=\mathrm{nf}(\mathrm{x}) \forall \mathrm{n} \in \mathrm{Z} \quad \text{... (4)} \end{array}$
$\begin{aligned} \text { Now } & \text { put } x=\frac{p}{q} \text { where } p, q \in Z, q \neq 0 \\ f\left(\frac{n p}{q}\right) & =n f\left(\frac{p}{q}\right) \forall n \in Z \\ \text { put } n & =q \\ & f(p)=q f\left(\frac{p}{q}\right) \end{aligned}$
$\Rightarrow \quad \mathrm{pf}(1)=\mathrm{qf}\left(\frac{\mathrm{p}}{\mathrm{q}}\right) \quad \{\text{from eq.(4)}\}$
Let $f(1)=a$
$\begin{array}{ll} \text { then } \quad & \mathrm{pa}=\mathrm{qf}\left(\frac{\mathrm{p}}{\mathrm{q}}\right) \\ & \mathrm{f}\left(\frac{\mathrm{p}}{\mathrm{q}}\right)=\frac{\mathrm{ap}}{\mathrm{q}} \\ \Rightarrow \quad & \mathrm{f}(\mathrm{x})=\mathrm{ax} \forall \mathrm{x} \in \mathbb{Q} \end{array}$
Now, $f\left(\frac{-3}{5}\right)=a\left(\frac{-3}{5}\right)=12 \Rightarrow a=-20$
$\Rightarrow \quad \mathrm{f}(\mathrm{x})=-20 \mathrm{x} \forall \mathrm{x} \in \mathbb{Q} \quad \text{... (5)}$
From the given functional equation it is not possible to find a unique function for irrational values of '$x$', there are infinitely many such functions satisfying given functional equation for irrational values of $x$, but in this problem we finally need the function at rational values of '$x$' only. So, for rational values of $x$ we are getting a unique function mentioned in (5).
Now, $g(x+y)=g(x) \cdot g(y)$
$\begin{array}{ll} \Rightarrow & \ln (\mathrm{g}(\mathrm{x}+\mathrm{y})=\ln (\mathrm{g}(\mathrm{x}))+\ln (\mathrm{g}(\mathrm{y})) \\ \text { Let } & \ln (\mathrm{g}(\mathrm{x}))=\mathrm{h}(\mathrm{x}) \\ \Rightarrow & \mathrm{h}(\mathrm{x}+\mathrm{y})=\mathrm{h}(\mathrm{x})+\mathrm{h}(\mathrm{y}) \\ \Rightarrow & \mathrm{h}(\mathrm{x})=\mathrm{kx} \forall \mathrm{x} \in \mathbb{Q} \\ \Rightarrow & \mathrm{g}(\mathrm{x})=\mathrm{e}^{\mathrm{kx}} \forall \mathrm{x} \in \mathbb{Q} \quad \text{... (6)} \end{array}$
$\begin{aligned} & \text { and } \quad \mathrm{g}\left(\frac{-1}{3}\right)=\mathrm{e}^{-\frac{\mathrm{K}}{3}}=2 \quad \Rightarrow \quad \mathrm{K}=-3 \ln 2 \\ & \Rightarrow \quad \mathrm{K}=\ln \left(\frac{1}{8}\right) \\ & \Rightarrow \quad \mathrm{g}(\mathrm{x})=\mathrm{e}^{\ln \left(\frac{1}{8}\right) \cdot \mathrm{x}}=\left(\frac{1}{8}\right)^x=2^{-3 \mathrm{x}} \forall \mathrm{x} \in \mathbb{Q} \end{aligned}$
Now, $f\left(\frac{1}{4}\right)=-5, g(-2)=2^6=64$
$\mathrm{g}(0)=1$
$\begin{aligned} \text{So} \quad & \left(\mathrm{f}\left(\frac{1}{4}\right)+\mathrm{g}(-2)-(8) \mathrm{g}(0)\right) \\ & =(-5+64-8)(1)=51 \end{aligned}$
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 _________.
Explanation:
$\begin{aligned} & \mathrm{f}(\mathrm{x})=\frac{\left(\mathrm{x}^{2023}+2024 \mathrm{x}+2025\right)}{\mathrm{e}^{\pi \mathrm{x}}\left(\mathrm{x}^2-\mathrm{x}+3\right)}(\sin \mathrm{x}+2) \\ & \because(\sin \mathrm{x}+2) \text { is never zero } \\ & \therefore \text { for } \mathrm{x}^{2223}+2024 \mathrm{x}+2025=0 \\ & \text { let } \phi(\mathrm{x})=\mathrm{x}^{2023}+2024 \mathrm{x}+2025 \\ & \phi^{\prime}(\mathrm{x})=2023 \mathrm{x}^{2022}+2024>0 \forall \mathrm{x} \in \mathrm{R} \\ & \therefore \phi(\mathrm{x}) \text { is an Strictly Increasing function } \\ & \therefore \phi(\mathrm{x})=0 \text { for exactly one value of } \mathrm{x} \\ & \therefore \mathrm{f}(\mathrm{x})=0 \text { has one solution } \end{aligned}$
$f(x)=a x^{2}+b x+c$ is an even function and
$g(x)=p x^{3}+q x^{2}+r x$ is an odd function.
If $h(x)=f(x)+g(x)$ and $h(-2)=0$, then $8 p+4 q+2 r=$
Which of the following function are odd?
I. $f(x)=x\left(\frac{e^x-1}{e^x+1}\right)$
II. $f(x)=k^x+k^{-x}+\cos x$
III. $f(x)=\log \left(x+\sqrt{x^2+1}\right)$
Define the function, $f, g$ and $h$ from $R$ to $R$ such that $f(x)=x^2-1, g(x)=\sqrt{x^2+1}$ and $h(x)= \begin{cases}0, \text { if } & x \leq 0 \\ x, \text { if } & x \geq 0\end{cases}$ consider the following statements
(i) fog is invertible
(ii) $h$ is an identify function
(iii) $f \circ g$ is not invertible
(iv) $(h \circ f \circ g) x=x^2$
Then, which one of the following is true ?






