Determine whether f(x) = 3x^4 - 5x^2 + 2 is even odd or neither.

A function is even if

f(-x) =
f(x)

In other words, plugging in a number will be the same as
plugging in the negative value of the same number.

We'll analyze the given
function, replacing each x by -x.

f(-x) = 3(-x)^4 - 5(-x)^2 +
2 

We'll compute raising -x to the 4th and 2nd powers and we'll
get:

(-x)^4 = (-x)(-x)(-x)(-x) = x^2*x^2 =
x^4

f(-x) = 3(x)^4 - 5(x)^2 + 2 

So we can see
that:

f(-x) = f(x) which means that the function f(x) is an even
function. 

An even function has symmetry across the y-axis. We also
know that if all of the exponents are even, then the function is even.