Given,
f(x)=[x]−x1
We know that, x=[x]+x where x is fractional part of x whose value is 0<x<1,
So, [x]−x=−x
Now putting the value in given function we get,
f(x)=[x]−x1
⇒f(x)=−x1
Now we know that g(x)1 is defined when g(x)>0, but −x∈(−1,0)
Hence, −x is not defined
Hence, Domain and Range will be=ϕ