First, let's zoom in and focus on the equation we are given. Let's square it. We get
\((a^2 - 2 + 1/a^2) = 0\)
This will achieve the equation
\(a^2 - 1/a^2 = -2\)
Next, let's focus on what we are trying to find. We know that
\(a^3 - 1/a^3 = ( a - 1/a) ( a^2 + 1 + 1/a^2)\)
WAIT! The first term in what we must find is 0!
That means our answer is just 0.
So 0 is our answer!
Thanks! :)