(1)1-x>0==>x0==>x>-3
∴函数f(x)的定义域这(-3,1)
(2)A^0=(1-x)*(x+3)=1==>x^2+2x-2=0==>x1=-1-√3,x2=-1+√3
(3)-x^2-2x+3=-(x+1)^2+4=1/a
当x=-1时f(x)极小值-1,4=1/a==>a=1/4