Assertion (A) : A function f : N $\rightarrow$ N given by f(x) = $x^3$ + 2, $\forall$ x $\in$ N is one-one but not onto. Reason (R) : Since $\forall$ y $\in$ N (Codomain), there does not exist x = (y - 2)$^{1/3}$ in N (Domain) such that f(x) = $x^3$ + 2 = y.

Year	Paper Code	Set	Position
CBSE 2026	Series 65-4	Set 1	Question 20
CBSE 2026	Series 65-4	Set 2	Question 20
CBSE 2026	Series 65-4	Set 3	Question 20

• Step 1: Stating the fundamental formula / law statement (+1 Mark)
• Step 2: Intermediate mathematical substitution or proof steps (+1 Mark)
• Step 3: Correct final value or conclusion with mandatory SI units (+1 Mark)