Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main 20236 AprilEvening Shift
Exam
JEE Main
Year
2023
Date
6 April
Shift
Evening Shift
Subject
Mathematics
Chapter
Functions

JEE Main 2023 · 6 April · Evening Shift · Mathematics · Functions

Let the sets A and B denote the domain and range respectively of...

Let the sets AandBA and B denote the domain and range respectively of the function f(x)=1[x]−xf\left(x\right) = \dfrac{1}{\sqrt{\left[x\right] - x}},where[x]where \left[x\right] denotes the smallest integer greater than or equal to xx. Then among the statements

\left(S1\right): A \cap B = \left(1, \infty\right) - \mathbb{N}and</p><p>(S2):A∪B=(1,∞)and</p><p>\left(S2\right): A \cup B = \left(1, \infty\right)

Options

  1. AOnly (S2)( S2 ) is true
  2. BOnly (S1)( S1 ) is true
  3. CNeither (S1)\left(S1\right) nor (S2)\left(S2\right) is true
  4. DBoth (S1)\left(S1\right) and (S2)\left(S2\right) are true

Correct answer

C. Neither (S1)\left(S1\right) nor (S2)\left(S2\right) is true

Step-by-step solution

Given,

f(x)=1[x]−xf\left(x\right) = \dfrac{1}{\sqrt{\left[x\right] - x}}

We know that, x=[x]+{x}x = \left[x\right] + \left\{x\right\} where \left\{x\right\}isfractionalpartofis fractional part ofxwhosevalueiswhose value is0 < \left\{x\right\} < 1,</p><p>So,[x]−x=−{x},</p><p>So, \left[x\right] - x = - \left\{x\right\}

Now putting the value in given function we get,

ff\left(x\right) = \dfrac{1}{\sqrt{\left[x\right] - x}}

⇒f(x)=1−{x}⇒ f\left(x\right) = \dfrac{1}{\sqrt{- \left\{x\right\}}}

Now we know that 1g(x)\dfrac{1}{\sqrt{g\left(x\right)}} is defined when g(x)>0g\left(x\right) > 0, but −{x}∈(−1,0)- \left\{x\right\} \in \left(- 1, 0\right)

Hence, −{x}\sqrt{- \left\{x\right\}} is not defined

Hence, Domain and Range will be=ϕ= ϕ

Practice Functions on Quantrex Academy →

More from Functions

Let ℕ denote the set of all positive integers. Consider the sets A = \ 1, 2, 3, 4, 5\ and… JEE Advanced 2026Let f:(1,∞)→ℝ be a function defined as f(x) = (x-1)/(x+1) . Let f^ i+1 (x) = f(f^i(x))… JEE Main 2026Let f be a polynomial function such that _2(f(x)) = ( _2(2+(2)/(3)+(2)/(9)+…∞))·… JEE Main 2026Let f: ℝ arrow ℝ be defined as f(x) = (2x^2 - 3x + 2)/(3x^2 + x + 3) . Then f is : JEE Main 2026Let e be the base of natural logarithm and let f: \ 1, 2, 3, 4\ arrow \ 1, e, e^2, e^3\… JEE Main 2026Let f: R arrow R be a function such that f(x) + 3f((π)/(2) - x) = x , x ∈ R . Let the… JEE Main 2026The sum of all the integral values of p such that the equation 3 ^2 x + 12 x - 3 = p , x… JEE Main 2026Let A = \ 1, 2, 3, 4, 5, 6\ . The number of one-one functions f: A arrow A such that f(1)… JEE Main 2026For the function f:[1,∞) arrow [1,∞) defined by f(x)=(x-1)^4+1 , among the two… JEE Main 2026Let for some α ∈ ℝ , f:ℝarrowℝ be a function satisfying f(x+y)=f(x)+2y^2+y+α xy for all… JEE Main 2026Let [·] denote the greatest integer function. If the domain of the function f(x) = ^ -1… JEE Main 2026The number of functions f: \ 1, 2, 3, 4\ arrow \ a, b, c\ , which are not onto, is: JEE Main 2026If the domain of the function f(x) = _ (0.6) (|(2x-5)/(x^2-4)|) is (-∞, a] \ b\ [c, d)… JEE Main 2026Given below are two statements: Statement I: The function f: R arrow R defined by… JEE Main 2026The sum of all the elements in the range of f(x)=Sgn( x)+Sgn( x)+Sgn( x)+Sgn( x) , x ≠ n… JEE Main 2026If g(x)=3 x^ 2 +2 x-3, f(0)=-3 and 4 g(f(x))=3 x^ 2 -32 x+72 , then f(g(2)) is equal to: JEE Main 2026 Full Functions list Functions JEE Maths PYQsJEE Mathematics PYQs All JEE Main PYQs