Q. On the set of integers $Z$, define $f:Z \rightarrow Z$ as $f(n) = \left\{ \begin{array}{r} \frac{n}{2},\ n\ is\ even \\ 0,\ \ \ n\ \ is\ odd \end{array} \right\}$, then $'f^{'}$is

A) Injective but not surjective
B) Neither injective nor surjective
C) Surjective but not injective
D) Bijective
Explanation

(c)
Given, $f(n) = \left\{ \begin{array}{r}
\frac{n}{2},\ n\ is\ even \\
0,\ \ \ n\ \ is\ odd
\end{array} \right.\$
Here, we see that for every odd values of $z$, it will give zero. It means that it is a many one function.
For every even values of $z$, we will get a set of integers $( - \infty,\ \infty)$. So, it is onto. Hence, it is surjective but not injective.

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.