What are three idempotents of the quotient ring $\displaystyle \mathbb{Q}[x]/(x^4+x^2) $?

So an element is of the form $\displaystyle a+x^2+x^4 $ where $\displaystyle a \in \mathbb{Q}[x] $. So $\displaystyle (a+x^2+x^4)^2 = a+x^2+x^4 $.

So one idempotent would be: $\displaystyle 0 $. The others would be just guess and check?