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CBSE Class 12 Mathematics 2026 Main Paper 65/4/1 · Q201 Marksinjectivity_surjectivity

CBSE Class 12 Mathematics 2026 Main Paper 65/4/1 · Question 20 (Relations And Functions)

Assertion: f:ℕ→ℕ, f(x)=x³+2 is injective but not onto. Reason: For every natural y there is no natural x with x³+2=y.

✅ Step-by-Step Solution

Final Answer: Assertion true, reason false.
  1. Strict increase proves injectivity and y=1 has no preimage. However y=3 has preimage x=1, so the universal claim in the reason is false.

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