The given function is an even function, as the polynomial has degree 6, and all the terms in the polynomial has even powers
As the values for " -x " and " x " are same, since they have even powers.
And if we observe the function properly,
[ graph of x⁶ - 2x² is symmetric about y - axis, and if we add 3, it shifts 3 units upside so there's no change to symmetry. ]
Conclusion : The graph is symmetric about y - axis.