The function [tex]f[/tex] is given by [tex]f(x)=0.1 \times 4-0.5 \times 3-3.3 \times 2+7.7 x-1.99[/tex]. For how many positive values of [tex]b[/tex] does [tex]\lim x \rightarrow b f(x)=2 ?[/tex]