Question:
Let $X=\{-1,0,2,5\}$ and $f: X \rightarrow R Z: f(x)=x^{3}+1$. Then, write $f$ as a set of ordered pairs.
Solution:
Given, $X=\{-1,0,2,5\}$
$f: X \rightarrow R Z: f(x)=x^{3}+1$
Finding f(x) for each value of x,
(1) $f(-1)=(-1)^{3}+1=-1+1=0$
(2) $f(0)=(0)^{3}+1=0+1=1$
(3) $f(2)=(2)^{3}+1=8+1=9$
(4) $f(5)=(5)^{3}+1=125+1=126$
f in ordered pair is represented as
$f=\{(-1,0),(0,1),(2,9),(5,126)\}$