Page 53 - Spotlight A+ SPM Additional Mathematics Form 4 & 5
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Answer   Additional Mathematics

                   7.  (a)   y                   2.  (a)  –2  f(x)  6        19.  g(x) =  9x + 38
                                                   (b)  Horizontal line test cut the
                                Q(5, 9)                                                  5
                                                       graph only at one point.
                                     y = x                                                 5 – 3x
                                                       Thus, the functon f(x) has    20.  (a)  g(x) =
                                                       an inverse function.                 2
                              M(a, b)  Q ′(9, 5)                                  (b)  –14
                       f(x)                      3.  (a)  Yes because each object in      –x – 1
                                    –1
                                  f (x)                                        21.  (a)  f(x) =
                                          x            set K has one image in set L.        6
                     P(0, –5)  0                   (b)  (i)  12    (ii)  2             43
                                                   (c)  Domain = {–3, 2, 3, 5}    (b)  –
                             P ′(–5, 0)                                                13
                     (b)  a = 4, b = 1                 Codomain = {5, 10, 12, 15}   22.  Has an inverse function
                               x      1                Range = {5, 10, 12, 15}
                         –1
                   8.  (a)  f  (x) =    (b)  –                     5           23.
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                              10     10          4.  (a)  –29   (b)                     y
                              x + 9                                12
                         –1
                   9.  (a)  f  (x) =                      13    9
                               2                 5.  (a)  m =   , n =                    19
                     (b)  8                               9 4   2                                 y = x
                         –1
                  10.  (a)  f  (x) =  x + 7        (b)  x =                            9
                               3                          2
                     (b)  4                            1                               2
                         –1
                  11.  (a)  g (x) =   5  , x ≠ 2    6.  (a)   6    (b)  12             0              x
                              x – 2                                                 –3    2   9   19
                         20                      7.  (a)  –2                          –3
                     (b)  –                        (b)  1
                          7                        (c)  –1  x  5                Domain of f  : 1  x  19
                                                                                           –1
                               3x                                                 Range of f  : –3  f(x)  2
                                                                                          –1
                         –1
                  12.  (a)  h (x) =   , x ≠ 4    8.  13
                              x – 4                      2                     24.  (a)
                         3x                      9.  –6 and                              f
                     (b)    , x ≠ 2                      3
                        x – 2                                                         14
                              x + 8   1         10.              y                                y = x
                         –1
                  13.  (a)  h (x) =   , x ≠
                              2x– 1   2                                                     f(x)
                        19                                     6
                     (b)                                                                       –1
                        21                                     5                       2      f  (x)        FORM 4 ANSWER
                         –1
                  14.  (a)  g (x) =   x  , x ≠ 1                                       0               x
                              x – 1                            2                           2       14
                        3
                     (b)                                                          (b)  a = 2, b = 14
                        2                                       0  1    x                x + 1
                               3                    –7     –5                  25.  (a)  (i)
                         –1
                  15.  (a)  g (x) =   , x ≠ 5      Range: 0  f(x)  6                     4
                              5 – x                                                           7x – 5
                        1                       11.                                  (ii)  g(x) =
                     (b)                                         y                              4
                        3                                                         (b)  6
                        14                                     16                           x – 1
                  16.  (a)                                                     26.  (a)  g (x) =
                                                                                      –1
                         5                                                                   4
                              9                                10
                     (b)  f(x) =   , x ≠ 1                                        (b)  fg(x) = 4x – 1
                             x – 1                                             27.  (a)  6
                         24                                    5                           2x – 9    11
                  17.  (a)  –                                                     (b)  gf(x) =   , x ≠
                         13                                     0       x                  11 – 2x   2
                     (b)  f(x) =   5x  , x ≠ –3      –5    –  10   2           28.   3
                                                            3
                             3 + x                 Range: 0  g(x)  16           4
                        7
                  18.  (a)                      12.  (a)  –9                   29.  (a)  Wrong because a = 21.
                        6                               4                             –1    x – 41
                     (b)  g(x) = 4 – 3x            (b)  –  3                      (b)  g (x) =   24
                        1                                                          11
                  19.  (a)                         (c)  gf(x) = 23 – 12x       30.
                        6                                                          5
                             2 – 2x             13.  h = 32k – 6
                     (b)  g(x) =   , x ≠ 0                                                  5x
                               x                14.  n = 5p – 2                31.  (a)  P(x) =   , x ≠ –1
                                                15.  p = 6 – 5pq                      1    1 + x
                                                16.  g(x) = 1 – 2x                (b)   9
                 Paper 1                        17.  g(x) = 6x – 11            32.  (a)  g (x) =   x + 9
                                                                                      –1
                                                        8x – 35
                                                                                             4
                   1.  (a)  –3   (b)  –  1      18.  g(x) =   3                       35
                                     5                                            (b)
                                                                                      6
                                                                                                      435
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