解:當(dāng)??$ 1 \leqslant x<2 $??時??$, \frac {1}{2} x^2=1 , $??即??$ x^2=2 , $??
解得??$ x_1=\sqrt{2}, x_2= -\sqrt{2} ($??不合題意, 舍去);
當(dāng)??$ 0 \leqslant x<1 $??時??$, \frac {1}{2} x^2=0 , $??即??$ x^2=0 , $??解得??$ x_1=x_2=0 ; $??
當(dāng)??$ -1 \leqslant x<0 $??時??$, \frac {1}{2} x^2=-1 , $??方程沒有實數(shù)根;
當(dāng)??$ -2 \leqslant x<-1 $??時??$, \frac {1}{2} x^2=-2 , $??方程沒有實數(shù)根.
綜上所述, 在??$ -2 \leqslant x<2 $??的范圍內(nèi)滿足??$ [x]=\frac {1}{2} x^2 $??的??$ x $??的值為??$ \sqrt{2} $??或??$ 0$??