Question

A relation ‘f’ is defined by f (x) = x${}^2$ - 2, where x $\in$ {−2,−1, 0, 3}. Is f a function?

• A. Yes
• B. No

Answer 1

The correct option is A Yes

Given,f (x) = x${}^2$ - 2, where x $\in$ {−2,−1, 0, 3}
$\therefore$ f (-2) = (-2)${}^2$ - 2
= 2

f (-1) = (-1)${}^2$ - 2
= −1

f (0) = 0${}^2$ - 2
= −2

f (3) = 3${}^2$ - 2
= 7
$\therefore$ f = {(−2,2), (−1,−1), (0,−2), (3,7)}
We note that each element in the domain of f has a unique image.
Hence, f is a function.