Page 17 - Spotlight A+ SPM Additional Mathematics Form 4 & 5
P. 17

Form
           4          Additional Mathematics    Chapter 6  Linear Law


                   SPM Simulation HOTS Questions


               Paper 1
              1.  The variable  x and  y are related by equation   y  = mx  − nx   Divide both
                                                                      2
                 y  = mx  – nx where m and n are constant.       x              side with x .
                                                                                       2
                       2
                 x                                y –            y      n
                             y                    x 2            x 3  = m −
                                                                        x
                                                                Compare to Y = mX + c.
                                        x     k + 2
                           O                                              y    1
                    ©PAN ASIA PUBLICATIONS
                                                                Hence Y =  , X =  , m = –n and c = m.
                                                                         x 3   x
                                                                From the graph,  c = k + 2
                                                              x               m = k + 2
                          –3k                    O
                                                                               k = m − 2 …❷
                             Diagram (a)                        To express m in terms of n, eliminate
                                                                variable k.
                             y                                                  n
        y                    x – 2                              As ❶ = ❷,  m − 2 =
                                                                                3
                                                                        3  m − 6 = n
                   x     k + 2
                                                                                n
      O                                                            m is the   m =   + 6
                                                                 subject        3
       CHAP                                                  2.  The variable x and y are related by an equation
        6                   O
                                                                       2
     –3k                                 x                     y  =  10 2x   +  1 . The diagram below shows a
                                                               straight line graph obtained by plotting
                             Diagram (b)                       log  y against x .
                                                                            2
                                                                  10
                 Diagram (a) and diagram (b) show the straight            log  y
                 line graphs obtained by plotting the relations             10
                 from the equation. Express  m in terms of  n.                      (p, 9)
                    C4
                  Examiner's Comment:
                                                                         q
                   In diagram (a)                                                      x 2
                                                                         O
                  x is the X-intercept.
                             y                                 Find the values of p and q.   C3
                  Then, reduce   = mx  − nx to get x as the
                                   2
                             x                                  Examiner's Comment:
                  variable of X.                                Convert the equation y = 10 2x  + 1  into the
                                                                                        2

                  y  = mx  − nx   Divide both                   linear form, Y = mX + c.
                        2
                                                                            2
                  x              side with x.                         y = 10 2x  + 1   Taking logarithm
                  y   = mx − n                                    log  y = log  10 2x  + 1   to the base of 10
                                                                                2
                                                                                       to both side.
                  x 2                                               10      10
                                                                            2
                  Compare to Y = mX + c.                          log  y = (2x  + 1) log  10
                                                                    10
                                                                                   10
                                                                           2
                           y                                      log  y = 2x  + 1
                                                                    10
                  Hence Y =  , X = x, m = m and c = −n.
                           x 2                                  Compare to Y = mX + c.
                  From the graph,  c = −3k                      Hence Y = log  y, X = x , m = 2 and c = 1.
                                                                                    2
                               −  n = −3k                                   10
                                   n                            From the graph,  q  = y-intercept
                                k =   …❶
                                   3                                              = 1
                   In diagram (b)                                     Gradient, m  = 2
                                                                           9 – 1
                  y   is the y-intercept.                                         = 2
                  x 3                                                      p – 0 p  = 8
                                                                              2
                             y                y
                  Then, reduce   = mx  − nx to get   as                        p  = 4
                                   2
                             x               x 3
                  variable of y.                                Thus, p = 4 and q = 1.
             118
   12   13   14   15   16   17   18   19   20   21   22