Page 17 - PBD Plus Matematik Tambahan T4 (EG)
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Praktis SPM 1






                                                                                                  Praktis Ekstra SPM 1
                                                                  4.  Dalam rajah di bawah, fungsi  f memetakan  y
             KERTAS        1
                                                                     kepada x dan fungsi g memetakan y kepada z.
             1.  Diberi fungsi m(x) = 3x dan n(x) = h – kx dengan    In the diagram below, the function f maps y to x and the
                                                                     function g maps y to z.
               keadaan  h dan  k ialah pemalar. Ungkapkan  h
               dalam sebutan k dengan keadaan nm(1) = 4.                          x    f   y   g    z
               It is given the functions m(x) = 3x and n(x) = h – kx where h and                     r
               k are constants. Express h in terms of k such that nm(1) = 4.
                SP 1.2.5                   [3 markah / 3 marks]                           q
                Jawapan / Answer :
                 nm(x) = h – k(3x)                                               p
                        = h – 3kx
                 nm(1) = 4                                                      –1
                h – 3k(1) = 4                                        (a)  Cari gf  (p).  SP 1.3.1
                                                                         Find gf  (p).
                                                                               –1
                 h – 3k = 4                                          (b)  Ungkapkan  q  dalam sebutan  p jika diberi
                      h = 4 + 3k                                               3y – 5
                                                                         f(y) =     , y ≠ 0.  SP 1.1.3
                                                                                 y                    3y – 5
                                                                         Express q in terms of p if it is given f(y) =   y  , y ≠ 0.
                                                                                                 [3 markah / 3 marks]
             2.  Diberi fungsi  f(x) =  px + 1,  g(x) = 3x – 5 dan          Jawapan / Answer :
               fg(x) = 3px + q. Ungkapkan p dalam sebutan q.         (a)  f(q) = p dan / and g(q) = r
               It is given the functions f(x) = px + 1, g(x) = 3x – 5 and     f (p) = q
                                                                          –1
               fg(x) = 3px + q. Express p in terms of q.   SP 1.2.5        gf (p) = g(q)
                                                                           –1
                                           [3 markah / 3 marks]                    = r
                Jawapan / Answer :  Penerbitan Pelangi Sdn. Bhd.
               fg(x) = p(3x – 5) + 1                                 (b)     f(q) = p
                    = 3px – 5p + 1                                        3q – 5  = p
                                                                            q
                 3px – 5p + 1 = 3px + q                                    3q – 5 = pq
                   –5p + 1  = q                                            3q – pq = 5
                      1 – q  = 5p                                        q(3 – p) = 5
                             1 – q                                                  5
                         p  =                                                  q =
                               5                                                   3 – p

                                                                  5.  (a)  Rajah di bawah menunjukkan hubungan
                                                                          antara set X dan set Y.
             3.  Diberi fungsi f(x) = 3x + 4 dan fg(x) = 6x + 7, cari         The diagram shows the relation between set X and set Y.
               Given functions f(x) = 3x + 4 and fg(x) = 6x + 7, find                 X    f(x)  Y
               (a)  fg(4),   SP 1.2.3
                                                                                      1 ●     ● 1
               (b)  g(x).   SP 1.2.4                                                  4 ●     ● 0.25
                                           [3 markah / 3 marks]                      10 ●     ● 0.1
                Jawapan / Answer :                                                    p ●     ● 0.04
               (a)  fg(4) = 6(4) + 7
                        = 31
                                                                          (i)  Dengan menggunakan tatatanda fungsi,
               (b)      fg(x) = 6x + 7                                        ungkapkan f dalam sebutan x.  SP 1.1.1
                                                                              Using the function notation, express f in terms of x.
                    3g(x) + 4 = 6x + 7
                       3g(x) = 6x + 3                                     (ii)  Cari nilai p.  SP 1.1.2
                        g(x) = 2x + 1                                         Find the value of p.
                                                                                                 [3 markah / 3 marks]






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