For f(x) to be a function, the value of x should not be repeated. That is no x value can be more then once.
So the required table is
[tex] x \ \ \ \ \ f(x)
\\
-1 \ \ \ \ \ \ 2
\\
2 \ \ \ \ \ -8
\\
6 \ \ \ \ \ -12 [/tex]
And for g(x) , not to be a function, we have to repeat x value that is
[tex] x \ \ \ \ \ \ g(x)
\\
-1 \ \ \ \ \ \ 2
\\
-1 \ \ \ \ \ \ -8
\\
6 \ \ \ \ \ \ -2 [/tex]
