English

Let f: R → R be defined by f(x) = 1x ∀ x ∈ R. Then f is ______.

Advertisements
Advertisements

Question

Let f: R → R be defined by f(x) = `1/x` ∀ x ∈ R. Then f is ______.

Options

  • One-one

  • Onto

  • Bijective

  • F is not defined

MCQ
Fill in the Blanks
Advertisements

Solution

Let f: R → R be defined by f(x) = `1/x` ∀ x ∈ R. Then f is f is not defined.

Explanation:

We have, f(x) = `1/x` ∀ x ∈ R

For x = 0, f(x) is not defined.

Hence, f(x) is a not define function.

shaalaa.com
  Is there an error in this question or solution?
Chapter 1: Relations And Functions - Exercise [Page 15]

APPEARS IN

NCERT Exemplar Mathematics Exemplar [English] Class 12
Chapter 1 Relations And Functions
Exercise | Q 37 | Page 15

RELATED QUESTIONS

Find the number of all onto functions from the set {1, 2, 3, ..., n} to itself.


Give an example of a function which is one-one but not onto ?


Which of the following functions from A to B are one-one and onto?
 f1 = {(1, 3), (2, 5), (3, 7)} ; A = {1, 2, 3}, B = {3, 5, 7}


Classify the following function as injection, surjection or bijection :

 f : Z → Z, defined by f(x) = x − 5 


Classify the following function as injection, surjection or bijection :

f : R → R, defined by f(x) = x3 + 1


Classify the following function as injection, surjection or bijection :

 f : R → R, defined by f(x) = x3 − x


Show that the exponential function f : R → R, given by f(x) = ex, is one-one but not onto. What happens if the co-domain is replaced by`R0^+` (set of all positive real numbers)?


Let f = {(3, 1), (9, 3), (12, 4)} and g = {(1, 3), (3, 3) (4, 9) (5, 9)}. Show that gof and fog are both defined. Also, find fog and gof.


Let R+ be the set of all non-negative real numbers. If f : R+ → R+ and g : R+ → R+ are defined as `f(x)=x^2` and `g(x)=+sqrtx` , find fog and gof. Are they equal functions ?


Give examples of two functions f : N → Z and g : Z → Z, such that gof is injective but gis not injective.


Find fog and gof  if : f(x) = `x^2` + 2 , g (x) = 1 − `1/ (1-x)`.


If f(x) = sin x and g(x) = 2x be two real functions, then describe gof and fog. Are these equal functions?


Consider f : R+ → [−5, ∞) given by f(x) = 9x2 + 6x − 5. Show that f is invertible with `f^-1 (x) = (sqrt (x +6)-1)/3 .`


Let f : R `{- 4/3} `- 43 →">→ R be a function defined as f(x) = `(4x)/(3x +4)` . Show that f : R - `{-4/3}`→ Rang (f) is one-one and onto. Hence, find f -1.


Let f  be a function from C (set of all complex numbers) to itself given by f(x) = x3. Write f−1 (−1).


If f : R → R is defined by f(x) = x2, find f−1 (−25).


Let A = {1, 2, 3, 4} and B = {ab} be two sets. Write the total number of onto functions from A to B.


If f : {5, 6} → {2, 3} and g : {2, 3} → {5, 6} are given by f = {(5, 2), (6, 3)} and g = {(2, 5), (3, 6)}, then find fog.    [NCERT EXEMPLAR]


Write the domain of the real function f defined by f(x) = `sqrt (25 -x^2)`   [NCERT EXEMPLAR]


Let fg : R → R be defined by f(x) = 2x + l and g(x) = x2−2 for all x

∈ R, respectively. Then, find gof.  [NCERT EXEMPLAR]


If the mapping f : {1, 3, 4} → {1, 2, 5} and g : {1, 2, 5} → {1, 3}, given by f = {(1, 2), (3, 5), (4, 1)} and g = {(2, 3), (5, 1), (1, 3)}, then write fog. [NCERT EXEMPLAR]


The  function f : [-1/2, 1/2, 1/2] → [-π /2,π/2], defined by f (x) = `sin^-1` (3x - `4x^3`), is

 


Which of the following functions from

\[A = \left\{ x \in R : - 1 \leq x \leq 1 \right\}\]

 


Let  \[f\left( x \right) = \frac{\alpha x}{x + 1}, x \neq - 1\] Then, for what value of α is \[f \left( f\left( x \right) \right) = x?\]

 


Let 
\[f : R \to R\]  be given by \[f\left( x \right) = x^2 - 3\] Then, \[f^{- 1}\] is given by 

 


The domain of the function f: R → R defined by f(x) = `sqrt(x^2 - 3x + 2)` is ______


Let D be the domain of the real valued function f defined by f(x) = `sqrt(25 - x^2)`. Then, write D


If f: R → R is defined by f(x) = x2 – 3x + 2, write f(f (x))


Let C be the set of complex numbers. Prove that the mapping f: C → R given by f(z) = |z|, ∀ z ∈ C, is neither one-one nor onto.


Using the definition, prove that the function f: A→ B is invertible if and only if f is both one-one and onto


Let A = {1, 2, 3, ...n} and B = {a, b}. Then the number of surjections from A into B is ______.


Let f : R → R be a function defined by f(x) `= ("e"^abs"x" - "e"^-"x")/("e"^"x" + "e"^-"x")` then f(x) is


Consider a set containing function A= {cos–1cosx, sin(sin–1x), sinx((sinx)2 – 1), etan{x}, `e^(|cosx| + |sinx|)`, sin(tan(cosx)), sin(tanx)}. B, C, D, are subsets of A, such that B contains periodic functions, C contains even functions, D contains odd functions then the value of n(B ∩ C) + n(B ∩ D) is ______ where {.} denotes the fractional part of functions)


Difference between the greatest and least value of f(x) = `(1 + (cos^-1x)/π)^2 - (1 + (sin^-1x)/π)^2` is ______.


The domain of function is f(x) = `sqrt(-log_0.3(x - 1))/sqrt(x^2 + 2x + 8)` is ______.


A function is called one-one if different elements of the domain have:


For \(f(x)=x^2+x\), if \(y=1\), which two domain elements have the same image?


Which condition represents an into function?


Which condition represents a many-one function?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×