From
#(x-1)^n = x^n + (n x^(n-1)(-1))/(1!)+(n(n-1)x^(n-2)(-1)^2)/(2!)+ cdots + #
Considering #n = 3/2# we have
#(x-1)^(3/2) - x^(3/2) = (3/2 x^(3/2-1)(-1))/(1!)+(3/2(3/2-1)x^(3/2-2)(-1)^2)/(2!)+cdots+# and
#((x-1)^(3/2)-x^(3/2))/sqrt(x) = (3/2 x^(3/2-1-1/2)(-1))/(1!)+(3/2(3/2-1)x^(3/2-2-1/2)(-1)^2)/(2!)+cdots+=#
#(3/2 x^0(-1))/(1!)+x^-1 f(x^-1)# then
#lim_{x\to\infty}((x-1)^(3/2)-x^(3/2))/sqrt(x) =lim_(x->oo) (3/2 x^0(-1))/(1!)+x^-1 f(x^-1) = -3/2#