Find by substituting for all occurrence of in .

Simplify each term.

Apply the product rule to .

Raise to the power of .

Multiply by .

Apply the product rule to .

Raise to the power of .

Multiply by .

Check if .

Since , the function is even.

The function is even

The function is even

Determine if Odd, Even, or Neither f(x)=x^4-3x^2+9