f(x)的定义域是【-2,2】
则f(x2-x-4)中-2<=x²-x-4<=2
x²-x-4>=-2
x²-x-2=(x-2)(x+1)>=0
x<=-1,x>=2
x²-x-4<=2
x²-x-6=(x-3)(x+2)<=0
-2<=x<=3
所以-2<=x<=-1,2<=x<=3
所以定义域是[-2,-1]∪[2,3]