解方程x2-|x|-2=0
解:( 1 )当x≥0时,原方程化为x2-x-2=0,解得:x1=2,x2=-1(不合题意,舍去)
( 2 )当x<0时,原方程化为x2 + x –2=0,解得:x1=1,(不合题意,舍去)x2= -2
∴原方程的根是x1=2, x2= - 2
( 3 )请参照例题解方程x2-|x-1|-1=0