Page 11 - Praktis Hebat 2021 - Additional Mathematics F4
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Additional Mathematics  Form 4  Answers
                  f bukan suatu fungsi satu dengan satu kerana     5.  (a)  gh(x) =   1
                  dua objek yang berlainan mempunyai satu imej         2(x + 1)
                  yang sama. Oleh itu, fungsi f tidak mempunyai        3x – 1
                  fungsi songsang.                               hg(x) =   x – 1
                                            x + 4
           32.  (a)  Since fg(x) = gf(x) = x, hence g(x) =   2   is an      g (x) = –   x – 1
                                                                  2
                  inverse function fg(x) = 2x – 4.                       x – 2
                                                x + 4            h (x) = 4x + 9
                                                                  2
                  Oleh sebab fg(x) = gf(x) = x, maka g(x) =
                  ialah fungsi songsang bagi fg(x) = 2x – 4.  2            9
              (b)  Since fg(x) = gf(x) = x, hence g(x) = 3x – 6 is an   (b)  x = 3, x = –   7
                  inverse function of fg(x) =   x   + 2.     6.  (a)  g(x) = 4 + 11x
                                     3
                  Oleh sebab fg(x) = gf(x) = x, maka g(x) = 3x – 6   (b)  (i)   x = –  11
                  ialah fungsi songsang bagi fg(x) =   x   + 2.          15
                                           3                     (ii)  gg (x) = x, x = –   2
                                                                       –1
                       x + 2             x – 11                                   5
           33.  (a)  f (x) =    (b)  f (x) =
                  –1
                                    –1
                         7                 3                7.  (a)  k = 5, m = 4, n = 9
                                         4                    (b)  x = 2, x = –1
                                    –1
           34.  (a)  f (x) = 5x – 5   (b)  f (x) =    – 2                –1
                  –1
                                         x                    (c)  Yes/ Ya, ff (x) = x
                       x + 1                3                    (i)   True because when / Benar kerana apabila
           35.  (a)  f (x) =    (b)  f (–4) = –                      x = –2, ff (–2) = –2
                                                                            –1
                  –1
                                    –1
                       1 – x                5                    (ii)  False because when / Palsu kerana apabila
                                        3x – 5
           36.  (a)  f(x) = 2x + 1   (b)  f(x) =                     x = 3, ff (3) = 3
                                                                           –1
                                          2
                                       4                    8.  (a)  (i)   f(–3) = –16
           37.  (a)  f(x) = –5x + 2   (b)  x =                   (ii)  m = 5
                                       5
                                        1                        (iii)  gf(x) = –27x + 73
           38.  (a)  x = 3      (b)  x = –
                                        6                     (b)                      73
           39.  (a)  f(3) = 2   (b)  m = 12, m = 16                x     –2      0     27      4
                    x + 5
           40.  f (x) =   3                                        y    127     73      0      35
               –1
                    4x – 7
              g (x) =
               –1
                      3x                                                       y
                 x  = 4                                                     140
                                                                             120
            PAPER 2                                                          100
            1.  (a)  x  –2    0    4     3                                   80
                                   3                                         60
                   f(x)  10   4    0     5                                   40
                                                                              20
                                f(x)                                                          x
                                                                        –2  –1  0  1  2  3  4
                               12
                               10
                               8                            9.  (a)  g(x) = 2x + 3
                               6                                  –1    7x – 4
                                                               (b)  g f(x) =
                               4                                      44  2
                               2                              (c)  x = –   21
                                              x
                                0
                        –2  –1      1   2   3              10.  (a)     f(x)
                                             7                         35  y = f(x)
              (b)  0 < f(x) < 10   (c)  x = 5, x = –                   30
                                             3                         25
            2.  (a)  g(–4) = –21   (b)  g(–2) = –12                    20
              (c)  x =2, x =   2                                       15
                         5                                             10
            3.  (a)  p = 2, q = 7                                       5                 y = f –1 (x)
              (b)  h(5) = 3                                        –10  –5  0  5  10  15  20  25  30  35  x
              (c)  x = 7                                               –5
            4.  (a)  fg(x) = 12x  – 4x + 80
                         2
                  gf(x) = 48x  – 4x + 20                      (b)  Domain: –7 < x < 29
                         2
                                                                                –1
                  fg(x) ≠ gf(x)                                  Range / Julat: 0 < f (x) < 6
                         5                                    (c)  x = 4, x = –3
              (b)  x = 4, x =
                         3
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     ANS HEBAT ADD MATH F4 1P.indd   2                                                             09/04/2021   3:50 PM
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