Answer
It is not a one-to-one function
Work Step by Step
$f(x) = \frac{1}{x^4}$
One to one if f(p) = f(q) and p = q
$f(p) = \frac{1}{p^4}$
$f(q) = \frac{1}{q^4}$
$ \frac{1}{p^4} = \frac{1}{q^4}$
$q^4 = p^4$
$p^4 - q^4 = 0$
$(p^2-q^2)(p^2 + q^2) = 0$
$(p-q)(p+q)(p^2 + q^2) = 0$
So p = q, p = -q
Thus it is not a one-to-one function
