CUET Mathematics 2026 21st May Shift 1 PYQs

Which of the following graphs represent a function ?

If the function $f: \mathbb{N} \rightarrow \mathbb{N}$ is defined as $f(n)=\left\{\begin{array}{ll}n-1, & \text { if } n \text { is even } \\ n+1, & \text { if } n \text { is odd }\end{array}\right.$, then

(A) f is injective

(B) f is into

(C) f is surjective

(D) f is invertible

The relation R on the set N of natural numbers defined as $R = \{(x,y): y = x+3 \text{ and } x \le 5\}$ is