Absolute Value of Even Power

Theorem
Let $x \in \R$ be a real number.

Let $n \in \Z$ be an integer.

Then:
 * $\size {x^{2 n} } = x^{2 n}$

Proof
From Even Power is Non-Negative:
 * $x^{2 n} \ge 0$

The result follows from the definition of absolute value.