10) [5 marks] Show that if f(r) and g(x) are both continuous on R with f(r) = g(r) for every r E Q, then f(x) = g(x) for all r ER. 11) [5 marks] Assume that f(x) is continuous on R, that f (x) 2 0 for all r E R and that lim f(x) =0 = lim f(x). I-+-00 F-+00 Show that there exists a de R such that f(x)