Question 409779
WRT x-axis:
{{{x^4 - (-y)^4 = 16 = x^4 - y^4}}}, so YES.
WRT y-axis:
{{{(-x)^4 - y^4 = 16 = x^4 - y^4}}}, so YES.
WRT origin:
{{{(-x)^4 - (-y)^4 = 16 = x^4 - y^4}}}, so YES.