(b) (c) Let A = {0,1,2). Find (4 - {(0,0))) A. Let f: R R and g: RR, R is the set of real numbers. Find f g and gof, where f(x) = x - 2 and g(x)= x + 4. State whether these functions are injective, surjective, or bijective. :: [8 marks] Triangular number (T) are defined by the number of dots that occur when arranged in equilateral triangles as shown in Figure Q3(e). Show that T = n(n+1) for every positive integer n. : Figure Q3(e) [8 marks]