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CUET · MATHS · PYQ PAPER 2023

If a function \(f: R \rightarrow R\) is defined by \(f(x)=x^2+1\), then the pre-images of 17 and -3 respectively are:

  1. A \(\varnothing,\{4,-4\}\)
  2. B \(\{3,-3\}, \varnothing\)
  3. C \(\{4,-4\}, \varnothing\)
  4. D \(\{4,-4\},\{2,-2\}\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(\{4,-4\}, \varnothing\)

Step-by-step Solution

Detailed explanation

For pre-images of 17: \(x^2 + 1 = 17\) \(x^2 = 16\) \(x = \pm 4\) Pre-images of 17 are \(\{-4, 4\}\). For pre-images of -3: \(x^2 + 1 = -3\) \(x^2 = -4\) No real solutions, so pre-images of -3 are \(\varnothing\).