Question 1073333
Neither
1. For the graph of a  relation to be symmetrical with respect to the x-axis,for every point (x,y), its reflection over the x-axis, point (X,-Y) must also be in the graph.
That means that changing y to -y, you get the same equation.
That cannot happen with a function,
because by definition a function assigns just one y value to every x.
It cannot assign y and -y for the same x.
2. I assume that means symmetry about the y=x line.
For that symmetry, if a point (x,y) is part of the graph, (y,x) must be part of the graph too.
That means that swapping the x and y variables you get the same equation.
Some functions could do that, but the only polynomial that can do that is the degree 1 polynomial f(x)=x or y=x.
If one of the variables has an exponent that the other does not have,
swapping variables cannot possibly yield the same equation.
 
{{{f(x)=-2x^3+4x^2-2x+1}}} is a polynomial in {{{x}}} .
Polynomials in {{{x}}} have graphs like
{{{graph(300,300,-10,10,-10,10,0.05(x+5)(x-1)(x-3)+1)}}} and {{{graph(300,300,-10,10,-10,10,0.05(x+5)(x+1)(x-2)(x-6))}}} .
With any luck,
a polynomial of even degree may be symmetrical with respect to the y-axis,
or a polynomial of odd degree may be symmetrical about the origin.