由y=log0.6x是减函数,知1=log0.60.6>a=log0.60.8>log0.61=0;由y=log1.1x是增函数,知b=log1.10.9<log1.11=0;由y=1.1x是增函数,知c=1.10.8>1.1=1,由此能比较a、b、c的大小.
【解析】
∵y=log0.6x是减函数,
∴1=log0.60.6>a=log0.60.8>log0.61=0;
∵y=log1.1x是增函数,
∴b=log1.10.9<log1.11=0;
∵y=1.1x是增函数,
∴c=1.10.8>1.1=1,
∴b<a<c.
故答案为:b<a<c.