Solve the equation - x^2 + x/root 2 + 1 = 0

(- x^2+1)^2 = (- x/sqrt2)^2
or x^4 - 2x^2 +1 = x^2/2
or 2 x^4 - 5 x^2 +2 =0
or 2 x^4 - 4x^2 - x^2 +2 =0
or 2x^2 ( x^2 - 2) - 1( x^2 -2) = 0
or ( 2x^2 -1 ) ( x^2 -2) =0
so x^2 = 1/2 & x^2 = 2
or x = _+ 1/sqrt2 & +_ sqrt2 answer