As the title says, I'm trying to find the basic name for this type of function or what it's similar to. This is the function (one exponent increases the other decreases):
x$^5$ + x$^4$y + x$^3$y$^2$ + x$^2$y$^3$ + xy$^4$ + y$^5$
I vaguely remember seeing this in IB Math but I can't remember what it was used in or what it was called.