设函数f(x)= (x>0),观察f1(x)=f(x)=,f2(x)=f[f1(x)]=,f3(x)=f[f2(x)]=,f4(x)=f[f3(x)]=,…根据以上事实,由归纳推理可得:当n∈N+且n≥2时,fn(x)=f[fn-1(x)]=________.
函数的定义域是.
设函数= 2(x≤0)的反函数为y =,则函数y =的定义域为________
log(3+2) = ____________
已知a = log0.8,b = log0.9,c = 1.1,则a,b,c的大小关系是___________
若lg2 = a,lg3 = b,则lg=_____________