Page 9 - Focus SPM 2022 - Additional Mathematics
P. 9

Additional Mathematics SPM  Chapter 1  Functions
              (c)  Complete the following:
                                                                Solution
                      Equation            Function              In the first diagram, x = 0, f(x) = 2
                                                                f(0) = p(0) + q = 2  ......................a
                      y = 2x  + 4
                           2
                                                                In the second diagram, x = 1, f(x) = 5
                                                                f(1) = p(1) + q = 5  ......................b
              Solution                                          From a, q = 2
              (a)  g : x → AB x  or   g(x) = AB x               Substitute into b,  p + 2 = 5
                  Penerbitan Pelangi Sdn Bhd. All Rights Reserved.
                          4
                                             4
              (b)  V : r →  —πr 3  or  V(r) =  —πr                             p = 3
                                                3
                          3                  3
              (c)  f : x → 2x  + 4   or   f(x) = 2x  + 4        Try this HOTS question
                          2
                                             2
                                                                 The following diagrams show the inputs of x into
                  Try Question 4 in ‘Try This! 1.1’              a function machine which produces output g(x).
         Form 4
                  SPM     Highlights                            Input x      Input x      Input x
                                                                               2
                                                                                            4
                                                                  0
                                                                     f            f            f
                           7
                                           49
                           6
                          –6                                            –2           2            14
                                           36                        Output g(x)  Output g(x)  Output g(x)
                          –7
                                                                 If g(x) = ax  + b, where a and b are constants,
                                                                         2
                          Set A           Set B                  determine the values of a and b.
                The diagram above shows the relationship between   Solution
                set A and set B.                                 a = 1, b = −2
                (a)  State the type of relation.
                (b)  Write the relation using function notation.
                Solution                                      (c)  Reciprocal functions
                (a)  Many-to-one relation                       1.  A reciprocal function is expressed in the form of
                (b)  f : x → x 2                                        k
                                                                  f(x) = —, x ≠ 0, where k is a constant.
                                                                        x
                                                                                         k
                                                                2.  The graph of function f(x) = — only approaches,
                                                                                         x
                  Example of HOTS                                 but does not touch the line x = 0 (y-axis). This
                             HOTS Question
                                                                  is because the solution of dividing any numbers
                The following diagrams show the inputs of x into a   with zero is undefined.
                function machine which produces output f(x).
                                                                   For  example, the following diagram shows the
                 Input x      Input x      Input x                                      1
                   0            1            2                    graph of function g(x) =   .
                                                                                      x + 1
                                                                                     y
                      f            f            f
                                                                               x = –1

                         2            5            8
                      Output f(x)  Output f(x)  Output f(x)                                     x
                                                                                    0
                If  f(x) =  px +  q, where  p and  q are constants,
                determine the values of p and q.






                  6
   4   5   6   7   8   9   10   11   12   13   14