Some functions and their graphs -i - class-XI
A comprehensive quiz on mathematical functions for Class XI, covering identity functions, constant functions, polynomial functions, linear functions, and rational functions, including properties like injectivity, continuity, periodicity, function composition, inverses, and functional equations.
Questions
If $p = q$ then $px =$ ________
- $q$
- $qx$
- $q + x$
- $0$
Which of the following functions are identity functions?
- $f:R\rightarrow R, f(x) = x$
- $g : N \rightarrow Z, g(p)= 3$
- $h:z \rightarrow z, h(y)=y$
- $g:N\rightarrow N, g(z) =z$
If ${ (x, 2), (4, y) }$ represents an identity function, then $( x, y)$ is :
- (2, 4)
- (4, 2)
- (2, 2)
- (4, 4)
Which of the following functions is/are constant ?
- $f(x)=x^{2}+2$
- $f(x)=x+\dfrac{1}{x}$
- $f(x)=7$
- $f(x)=6+x$
An identity function is a?
- Many to many function
- One to One function
- Many to one function
- None
State whether the following statement is True or False.
The inverse of an identity function is the identity function itself.
- True
- False
Let $f:\mathbb{R}\rightarrow \mathbb{R}$ be a function such that for any irrational number $r,$ and any real number $x$ we have $f(x)=f(x+r)$. Then, $f$ is
- an identity function
- a constant function
- a zero function
- onto function
The graph of an Identity function is?
- A straight line parallel to X axis
- A straight line parallel to Y axis
- A straight line passing through the origin
- None
Let $f$ be a linear function for which $f (6) - f (2) = 12$. The value of $f (12) - f(2)$ is equal the
- $12$
- $18$
- $24$
- $30$
The set values of $x$ for which function $f(x)=x\ln {x}-x+1$
- $\left( 1,\infty \right) $
- $\left( \cfrac { 1 }{ e } ,\infty \right) $
- $[e,\infty )$
- $\left( 0,1 \right) \cup \left( 1,\infty \right) $
Let $f$ be an injective map with domain {x, y, z} and range {1, 2, 3} such that exactly one of the following statements is correct and the remaining are false :
$f (x) = 1, f (y) \sqrt 1, f (z) \sqrt 2$. The value of $f^{-1} (1)$ is
- x
- y
- z
- none of these
$c \to c,,is,defined,as,f\left( x \right) = \frac{{ax + b}}{{cx + d}},,bd \ne 0$.then f is a constant function when
- a=c
- b=d
- ad=bc
- ab=cd
$f:c \to c$ is defined as $f(x) = \dfrac{{ax + b}}{{cx + d}},bd \ne 0$ then $f$ is a constant function when,
- a=c
- b=d
- ad=bc
- ab=cd
If $f(n+1)=f(n)$ for all $n\in N, f(7)=5$ then $f(35)=$
- $25$
- $49$
- $35$
- $5$
Let $f(x)$ is a cubic polynomial with real coefficients, $x\ \in R$ such that $f"(3)=0,\ f'(5)=0$
If $f(3)=1$ and $f(5)=-3$, then $f(1)$ is equal to
- $2$
- $3$
- $5$
- $6$
The complete set of values of $x$ for which the function $f(x)=2\tan^{-1}x+\sin^{-1} \dfrac{2x}{1+x^{2}}$ behaves like a constant function with positive output is equal to
- $x \in [-1,1]$
- $[1,\infty)$
- $(-\infty,1]$
- $(-\infty, -1] \cup [1,\infty)$
Let f be a polynomial function such that $f(3x)=f'(x).f"(x)$, for all $x\epsilon R$. Then :
- $f(2)+f'(2)=28$
- $f"(2)-f'(2)=0$
- $f"(2)-f(2)=4$
- $f(2)-f'(2)+f"(2)=10$
If $f \left( \dfrac { x + y } { 2 } \right) = \dfrac { f ( x ) + f ( y ) } { 2 }$ for all $x , y \in R$ and $f ^ { \prime } ( o ) = - 1 , f ( o ) = 1$ then $f(2)=$
- $\dfrac { 1 } { 2 }$
- $1$
- $-1$
- $\dfrac { -1 } { 2 }$
let $f(x)$ be a polynomial of degree $4$ having extreme values at $x=2$.if $\underset { x\rightarrow 0 }{ lim } \left( \frac { f\left( x \right) }{ { x }^{ 2 } } +1 \right) =3$ then $f(1)$
- $\frac { 1 }{ 2 } $
- $\frac { 3 }{ 2 } $
- $\frac { 5 }{ 2 }$
- $\frac { 9 }{ 2 } $
If $\alpha$ and $\beta$ are the polynomial $f(x)=x^2-5x+k$ such that $\alpha-\beta=1$, then value of k is
- $8$
- $6$
- $\dfrac{13}{2}$
- $4$
If $y^2 = ax^2 +bx+c$, then $y^2 \dfrac{d^2y}{dx^2}$ is
- a constant function
- a function of x only
- a function of y only
- a function of both x and y
If $fxln\left(1+\dfrac{1}{x}\right)dx=p(x)ln\left(1+\dfrac{1}{x}\right)+\dfrac{1}{2}x-\dfrac{1}{2}ln(1+x)+c$, being arbitary costant, then
- $p(X)=\dfrac{1}{2}x^{2}$
- $p(x)=0$
- $p(x)=1$
- $none\ of\ these$
Let $f(x)$ is cubic polynomial with real coefficient such that $f''(3) = 0, f'(5) = 0$. If $f(3) = 1$ and $f(5) = -3$, then $f(1)$ is equal to
- $2$
- $3$
- $5$
- $6$
$f (x) = x^4 - 10x^3 + 35x^2 - 50x + c$ is a constant. the number of real roots of . f (x) = 0 and
f'' (x) = 0 are respectively
- 1 , 0
- 3, 2
- 1 , 2
- 3 , 0
Let $\displaystyle f(x)=ax^{2}+bx+c,$ where $a,b,c$ are rational, and $f: Z\rightarrow Z,$ where $Z$ is the set of integers. Then $a+b$ is
- a negative integer
- an integer
- nonintegral rational number
- none of these
The positive integers $x$ for which $f(x)=x^{3}-8x^{2}+20x-13$ is a prime is
- $2$
- $3$
- $4$
- $5$
If $f\quad \left( x \right) ={ x }^{ 2 }+2bx+{ 2c }^{ 2 }\quad and\quad g\quad (x)\quad ={ -x }^{ 2 }\quad -2cx+{ b }^{ 2 }\quad are\quad such\quad that\quad min\quad f\quad (x)\quad >\quad max\quad g\quad (x),\quad then$ relation between b and c, is
- none relation
- 0 < c < b/2
- $\left| c \right| <\frac { \left| b \right| }{ \sqrt { 2 } } $
- $\left| c \right| >\sqrt { 2 } \left| b \right| $
If $f(x)$ is a polynomial function satisfying $f(x)f\left(\dfrac{1}{x}\right)=f(x)+\left(\dfrac{1}{x}\right)$ and $f(3)=28$, then $f(4)=$
- $63$
- $65$
- $66$
- $27$
If $f\left(x\right)$ is a polynomial such that $ f\left(a\right) f\left(b\right)<0$, then number of zeros lieing between $a$ and $b$ is
- $one$
- $at least one$
- $two$
- $at most 2$
If $ P ( X ) = x ^ { 3 } - 3 x ^ { 2 } + 2 x + 5 $ and P ( a ) = P ( b ) = P ( c ) = 0 then the value of ( 2 - a ) ( 2 - b ) ( 2 - c ) is
- 3
- 5
- 7
- 9
If f : R $\rightarrow$ R, g : R $\rightarrow$ R and h : R $\rightarrow$ R is such that $f(x) = x^2, g(x) = tan x$ and $h(x) = log x$, then the value of [ho(gof)], if $x = \displaystyle \dfrac{\pi}{2}$ will be
- 0
- 1
- -1
- 10
If f is a constant function and f(100)=100 then f(2007)=_____
- 2007
- 100
- 0
- None of these
The number of elements of an identity function defined on a set containing four elements is______
- $\displaystyle 2^{2}$
- $\displaystyle 2^{4}$
- $\displaystyle 2^{8}$
- $\displaystyle 2^{16}$
On differentiating an identity function, we get?
- Signum function
- Sinc function
- Constant function
- None
If $f,g,h$ are three functions from a set of positive real numbers into itself satisfying the condition,
$f(x) \cdot g(x)=h \sqrt{x^2 + y^2}$ such that $x,y \epsilon (0,\infty)$.then, $\dfrac{f(x)}{g(x)}$ is a?
- Constant function
- Identity function
- Zero function
- Signum function
A constant function is a periodic function.
- True
- False
Let $f(-2, 2)\rightarrow(-2, 2)$ be a continuous function given $f(x)=f{(x}^{2})$. Given $f(0)=\dfrac{1}{2}$ then the $4f(\dfrac{1}{2})$
- $4$
- $2$
- $-2$
- $1$
If $f\left( x \right)$ is a function satisfying $f\left( x \right).f\left( {\frac{1}{x}} \right) = f\left( x \right) + f\left( {\frac{1}{x}} \right)$ and $f\left( 4 \right) = 65$ then find $f\left( 6 \right)$
- $217$
- $215$
- $-216$
- $-217$
Let $f\left( x \right) = p{x^2} + qx - \left( {{a^2} + {b^2} + {c^2} - ab - bc - ca} \right),,\left( {p,q,a,b,c \in R} \right)(a,b,c$ are distinct). If both roots of $f(x)=0$ are non-real, then
- $2\left( {p + q} \right) - \left[ {{{\left( {a - b} \right)}^2} + {{\left( {b - c} \right)}^2} + {{\left( {c - a} \right)}^2}} \right] > 0$
- $2\left( {p + q} \right) - \left[ {{{\left( {a - b} \right)}^2} + {{\left( {b - c} \right)}^2} + {{\left( {c - a} \right)}^2}} \right] < 0$
- $p - 2q - 2 - \left[ {{{\left( {a - b} \right)}^2} + {{\left( {b - c} \right)}^2} + {{\left( {c - a} \right)}^2}} \right] < 0$
- $p - 2q - 2 - \left[ {{{\left( {a - b} \right)}^2} + {{\left( {b - c} \right)}^2} + {{\left( {c - a} \right)}^2}} \right] > 0$
If $f(x)$ is a polynomial function satisfying the condition $f(x) \times f\left(\dfrac{1}{x}\right)=f(x)+f\left(\dfrac{1}{x}\right)$ and $f(2)=9$ then
- $2f(4) =3 f(6)$
- $14f(1) = f(3)$
- $ 9f(3) = 2f(5)$
- $f(10) = f(11)$
If $\displaystyle f(x)=27x^{3}+\frac{1}{x^{3}}$ and $\alpha,\beta$ are the roots of $\displaystyle 3x+\frac{1}{x}=2$ is
- $f(\alpha)=f(\beta)$
- $f(\alpha)=10$
- $f(\beta)=-10$
- none of these
If a function satisfies $(x-y)f(x+y)-(x+y)f(x-y)=2(x^{2}y-y^{3}),\forall x,y\in R$ and $ f(1)=2,$ then
- $f(x)$ must be polynomial function
- $f(3)=12$
- $f(0)=0$
- $f(x)$ may not be differentiable
If $g(x)$ is a polynomial satisfying $g(x) g(y) = g(x) + g(y) + g(xy) - 2$ for all real $x$ and $y$ and $g(2) = 5$ then $g(3)$ is equal to -
- $10$
- $24$
- $21$
- none of these
Write a rational function $f$ that has vertical asymptote at $x=4$, a horizontal asymptote at $y=5$ and a zero at $x=-7$.
- $f(x)=\dfrac{5(x-7)}{(x-4)}$
- $f(x)=\dfrac{5(x+7)}{(x-4)}$
- $f(x)=\dfrac{5(x-7)}{(x+4)}$
- $f(x)=\dfrac{(x+7)}{(x+4)}$
A large mixing tank currently contains $200$ gallons of water into which $10$ pounds of sugar have been mixed. A tap will open pouring $20$ gallons per minute of water into the tank at the same time sugar is poured into the tank at a rate of $2$ pound per minute. Find the concentration (pounds per gallon) of sugar in the tank after $14$ minutes. Then
- the concentration is greater than at the beginning?
- the concentration lesser than at the beginning?
- the concentration equal to the concentration at the beginning?
- None of the above