The set of all polynomials with rational coefficients in dense in both spaces, the space of all continous functions defined in [a,b] C_([a,b]) with the metric ρ(f,g)=max┬(1≤t≤n)〖|f(t)- g(t)|〗 ( i hope you understand what i wrote ... prbl i will find a way to use mathml to write nicer ... :D ) Basically, if A is the set of all rational etc. , and C the countinous function space, the whole problem comes down to prooving A⊂[C], which implies to proove that the set of all polynomials has polynomial functions ( i.e. P[X] = f(x) ) which are continous ( from now on i use the metric from the space C, and that's it ) am i write ? p.s. i don't want a demonstration, becouse i want to learn how to do it myself Thanks !!!!!!