Answer
$x^2-2=0$
Work Step by Step
As we are given that solution set : {$-\sqrt 2,\sqrt 2$}
This implies that $x=-\sqrt 2,\sqrt 2$
As per zero-product reverse property, we have $(x+\sqrt 2)(x-\sqrt 2)=0$
Now, apply FOIL METHOD
$(x+\sqrt 2)(x-\sqrt 2)=0\implies x^2-2=0$
or, $x^2-2=0$
