Question:
Express the function f : X → R given by f(x) = x3 + 1 as set of ordered pairs, where X = {−1, 0, 3, 9, 7}. [NCERT EXEMPLAR]
Solution:
The function f : X → R is defined by f(x) = x3 + 1, where X = {−1, 0, 3, 9, 7}.
Now,
$f(-1)=(-1)^{3}+1=0$
$f(0)=0^{3}+1=1$
$f(3)=3^{3}+1=28$
$f(7)=7^{3}+1=344$
$f(9)=9^{3}+1=730$
So, $f=\{(x, f(x)): x \in X\}=\{(-1,0),(0,1),(3,28),(7,344),(9,730)\}$