Home
Class 12
MATHS
Let f : {x,y, z} to {a, b, c} be a one-o...

Let f : {x,y, z} `to` {a, b, c} be a one-one function. If it is known that only one of the following statements is true,
(i) `f(x)neb` (ii) `f(y)=b`
(iii) `f(z)nea`
Determine `f^(-1)(b)`.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem step by step, we need to analyze the given statements and determine which one is true, while also ensuring that the function \( f \) remains one-to-one. ### Step 1: Understand the function and its properties We have a function \( f: \{x, y, z\} \to \{a, b, c\} \) that is one-to-one. This means each element in the domain maps to a unique element in the range, and no two elements in the domain can map to the same element in the range. ### Step 2: Analyze the statements We are given three statements: 1. \( f(x) \neq b \) 2. \( f(y) = b \) 3. \( f(z) \neq a \) Only one of these statements is true. ### Step 3: Case Analysis We will analyze each case based on the assumption that one of the statements is true and the others are false. #### Case 1: Assume \( f(x) \neq b \) is true - If \( f(x) \neq b \) is true, then: - \( f(y) \) must be \( b \) (false), so \( f(y) \neq b \). - \( f(z) \) must be \( a \) (false), so \( f(z) = a \). This leads to: - \( f(x) \) can be either \( a \) or \( c \). - If \( f(z) = a \), then \( f(x) \) must be \( c \) (to keep it one-to-one). - But then \( f(y) \) cannot be \( b \), which contradicts our assumption. Thus, Case 1 is not valid. #### Case 2: Assume \( f(y) = b \) is true - If \( f(y) = b \) is true, then: - \( f(x) \neq b \) (false), so \( f(x) = b \). - \( f(z) \neq a \) (false), so \( f(z) = a \). This leads to: - \( f(y) = b \) - \( f(x) \) must be either \( a \) or \( c \). - If \( f(z) = a \), then \( f(x) \) must be \( c \) (to keep it one-to-one). However, this contradicts the one-to-one property since both \( f(x) \) and \( f(y) \) cannot map to \( b \). Thus, Case 2 is also not valid. #### Case 3: Assume \( f(z) \neq a \) is true - If \( f(z) \neq a \) is true, then: - \( f(x) \neq b \) (false), so \( f(x) = b \). - \( f(y) = b \) (false), so \( f(y) \neq b \). This leads to: - \( f(z) \) must be \( c \) (since it cannot be \( a \)). - \( f(x) = b \) and \( f(y) \) must be \( a \) (to keep it one-to-one). So, we have: - \( f(x) = b \) - \( f(y) = a \) - \( f(z) = c \) This satisfies the one-to-one condition. ### Step 4: Determine \( f^{-1}(b) \) Since we found that \( f(x) = b \), we conclude that: \[ f^{-1}(b) = x \] ### Final Answer Thus, the value of \( f^{-1}(b) \) is \( x \). ---
Doubtnut Promotions Banner Mobile Dark
|

Topper's Solved these Questions

  • FUNCTION

    FIITJEE|Exercise ASSIGNMENT PROBLEMS (OBJECTIVE) Level-I|47 Videos
  • FUNCTION

    FIITJEE|Exercise ASSIGNMENT PROBLEMS (OBJECTIVE) Level-II|20 Videos
  • FUNCTION

    FIITJEE|Exercise ASSIGNMENT PROBLEMS (SUBJECTIVE) Level-I|24 Videos
  • ELLIPSE

    FIITJEE|Exercise NUMERICAL BASED|4 Videos
  • HEIGHTS & DISTANCE

    FIITJEE|Exercise ASSIGNMENT PROBLEMS (OBJECTIVE) LEVEL-II|20 Videos

Similar Questions

Explore conceptually related problems

Let f:{x,y,z}rarr{1,2,3} be a one-one mapping such that only one of the following three statements is true and remaining two are false: f(x)!=2,f(y)=3,f(z)!=1 ,then-

Let f be a one-one function with domain {x,y,z} and range {1,2,3}. It is given that exactly one of the following statements is true and the remaining two are false f(X)=1,f(y)!=1f(z)!=2 determine f^(-1)(1)

Knowledge Check

  • Consider that f : A rarr B (i) If f(x) is one-one f(x_(1)) = f(x_(2)) hArr x_(1) = x_(2) or f'(x) ge 0 or f'(x) le 0 . (ii) If f(x) is onto the range of f(x) = B. (iii) If f(x) and g(x) are inverse of each other then f(g(x)) = g(f(x)) = x. Now consider the answer of the following questions. Let f be one-oe function with domain {x, y, z} and range {1, 2, 3}. It is given that exactly one of the following statement is true and the remaining two are false. f(x) = 1, f(y) != 1, f(z) != 2 , then the value of f^(-1)(1) is

    A
    x
    B
    z
    C
    y
    D
    Does not exist
  • 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

    A
    x
    B
    z
    C
    y
    D
    none of these
  • 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) ne 1,f (z) ne 2. The value of f^(-1) (1) is

    A
    x
    B
    y
    C
    z
    D
    none of these
  • Similar Questions

    Explore conceptually related problems

    Let f:{x,y,z}rarr[a,b,c] be a one-one fun and only one of the conditions (i) f(x)!=b, (ii) f(y)=b, (ii) f(2)!=a is true thenthe function fis given by the set

    Let f be a one-one function with domain (21,22,23) and range {x,y,z). It is given that exactly one of the following statements is true and the remaining two are false.f(21)=x;f(22);f(23)!=y. Then f^(-1)(x) is

    Let A={x:-1 le x le 1}=B be a function f: A to B. Then find the nature of each of the following functions. (i) f(x) = |x| " (ii) " f(x)=x|x| (iii) f(x)=x^(3) " (iv) " f(x)="sin"(pi x)/(2)

    If f(x)=sin(pi x), then draw the graph of the followings :(i)y=f(|x|)( ii) y=f(-|x|) (iii) |y|=f(x)

    Let f(x) be linear functions with the properties that f(1) le f(2), f(3) ge f(4) " and " f(5)=5. Which one of the following statements is true?