[ x^2/3-2x^1/3-3=0 ] * 3
x^2 - 2x - 9 = 0
-(-2)+/- sqrt[( - 2)^2 - 4(-9)] 2+/-sqrt40
x = --------------------------------------- = -------------------
2 2
2+/- 2sqrt10 2( 1+/ - sqrt10 )
x = ------------------- = ------------------------- = 1+/- sqrt10
2 2
x = 1+sqrt10
x = 1 - sqrt10