Answer:
even function
Explanation:
recall that:
a function is EVEN if and only if f(-x) = f(x) for all x in the domain of f
a function is ODD if and only if f(-x) = -f(x) for all x in the domain of f
we observe that for the function
f(x) = 3x^4
because x has been raised to an even power, that f(x) will always be positive (or zero), regardless of whether x is negative or positive.
i.e
f(x) = f(x) and f(-x) = f(x)
This behavior is described by the definition of an EVEN function (given above)
Hence f(x) is an even function