Which one of the following functions on $(0,1]$ can be extended to a
continuous function on $[0,1]$?
\correct $f(x)=x\cos(1/x)$
\wrong $f(x)=\frac{\cos x}x$
\wrong $f(x)=\cos(1/x)$
\wrong $f(x)=\frac{x+1}{x^3+2x^2+x}$
\wrong $f(x)=\hbox{max}(x,1/x)$
