Extra Class In Mathematics Practice Paper #2September 2, 2010 1. If h(x) = 1 + 3x and k(x) = x +2( CXC 1999 # 5 ) evaluate: a) hk (x) b) hk(4) c) (hk)-1 (x)5 marks 2. Given that : f : x 3 – x and g: x x + 2 x – 5 a) Calculate g(2) b) State the value of x for which g(x) is NOT defined c) Derive an expression for gf(x) d) Calculate the value of f-1 (4) e) Derive an expression for g-1 (x) 12 marks ( CXC 2000 #5 ) . Given that f(x) = x2 and g(x) = 5x + 3 Calculate : a) f(-2) b) gf(-2) c) g-1(x) 7 marks (CXC 1998 # 6) 4. Given that f(x) = 2×2 + 2x -1 , copy and complete the table below |x |-3 |-2 |-1 |0 |1 |2 |3 | |f(x) | |3 | |-1 | |11 |23 | b)Using 1 cm to represent 1 unit on the x-axis and 1 cm to represent 5 nits on the y-axis, draw the graph of f(x) = 2×2 + 2x -1 for the values of x in the domain -3 ? x ? 2 . c)On the graph of f(x) = 2×2 + 2x -1 , draw in the axis of symmetry for f(x) , and state the value of x where this occurs. d)From your graph, obtain estimates for: – The values of x for which f(x) = 0 – The set of values of x for which f(x) < x – The least value f(x) can take. 15 marks ( CXC 1998 #9)