Medium MCQ +4 / -1 PYQ · JEE Mains 2021

Let f, g : N $\to$ N such that f(n + 1) = f(n) + f(1) $\forall$ n$\in$N and g be any arbitrary function. Which of the following statements is NOT true?

  1. A If g is onto, then fog is one-one Correct answer
  2. B f is one-one
  3. C If f is onto, then f(n) = n $\forall$n$\in$N
  4. D If fog is one-one, then g is one-one

Solution

$f(n + 1) = f(n) + 1$<br><br>$f(2) = 2f(1)$<br><br>$f(3) = 3f(1)$<br><br>$f(4) = 4f(1)$<br><br>.....<br><br>$f(n) = nf(1)$<br><br>$f(x)$ is one-one

About this question

Subject: Mathematics · Chapter: Sets, Relations and Functions · Topic: Sets and Operations

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