X2+2X+1-a2<0X2+2X+1<塌旅前团清a2(X+1)2X+1x<镇衡a-1
解:x^2+2x+1-a^2=(x+1)^2-a^2<0即(x+1)^2当a>0时有嫌咐解轿晌。当a<=0时芹帆纯无解a>0时有|x+1|解得:-a-1
x^2+2x+1-a^2=(x+1)^2-a^2<0即(x+1)^2当乎渗a=0时无解a>0时有|x+1|解得:-a-1a<缺历0时有|x+1|<-a解岁扮脊得:a-1