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Matematik Tambahan  Tingkatan 4  Bab 2 Fungsi Kuadratik

                 PBD    2.2  Jenis-jenis Punca Persamaan Kuadratik                                               Buku Teks
                 PBD
                 PBD
                                Types of Roots of Quadratic Equations                                            ms. 45 – 48
                      FOKUS TOPIK



                  1.  Jenis-jenis punca persamaan kuadratik ditentukan oleh nilai pembezalayan, b  − 4ac.
                                                                               2
                                                                             2
                     The types of roots of quadratic equations are determined by the value of discriminant, b  − 4ac.
                                                            Jenis-jenis punca
                                                              Types of roots
                                Dua punca nyata                                    Tiada punca nyata / No real roots
                                  Two real roots                                           b  − 4ac  0 Jenis-jenis punca
                                                                                            2
                     Find the discriminant and determine the type of roots of each of the following quadratic equations. Reserved


                                                                                                    Types of roots of
                        b  − 4ac  0
                                            b  − 4ac = 0
                         2
                                             2
                     Berbeza / Different    Sama / Equal                                            persamaan kuadratik
                                                                                                    quadratic equations
                                                                                             VIDEO
                  7.  Cari nilai pembezalayan dan tentukan jenis punca bagi setiap persamaan kuadratik berikut.  TP1    TP2
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                                                                                                      SP 2.2.1
                                                      (a)  x  = 2(x – 5)               (b)  5x  – 4x = 5
                                                                                             2
                                                           2
                       2
                      x  = 3x – 1
                                                                   x  = 2x – 10             5x  – 4x – 5 = 0
                                                                                             2
                                                                    2
                        x  – 3x + 1 = 0                    x  – 2x + 10 = 0
                       2
                                                           2
                                                                                                       2
                                                                                            2
                       b  – 4ac = (–3)  – 4(1)(1)                                          b  – 4ac = (–4)  – 4(5)(–5)
                       2
                                   2
                                                           2
                                                                       2
                              = 5  0                     b  – 4ac = (–2)  – 4(1)(10)             = 116  0
                                                                 = –36  0
                      Mempunyai  dua  punca  nyata                                         Mempunyai dua punca nyata
                      dan berbeza.                        Tidak mempunyai punca nyata.     dan berbeza.
                      Has two real and different roots.   Has no real roots.               Has two real and different roots.
                      (c)  –3x  – 7x = –6             (d)  9x  – 12x + 4 = 0           (e)  3x  = 7(x – 5)
                                                            2
                                                                                             2
                            2
                       –3x  – 7x + 6 = 0                  b  – 4ac = (–12)  – 4(9)(4)              3x  = 7x – 35
                                                           2
                         2
                                                                                                     2
                                                                        2
                                                                  = 0                       3x  – 7x + 35 = 0
                                                                                             2
                      b  – 4ac = (–7)  – 4(–3)(6)
                                  2
                       2
                             = 121  0                    Mempunyai dua punca nyata        b  – 4ac = (–7)  – 4(3)(35)
                                                                                                       2
                                                                                            2
                                                          dan sama.                               = –371  0
                      Mempunyai dua punca nyata dan       Has two equal real roots.
                      berbeza.                                                             Tidak mempunyai punca nyata.
                      Has two real and different roots.                                    Has no real roots.
                  8.  Selesaikan setiap yang berikut.   SP 2.2.2     TP3
                     Solve each of the following.
                                                                      (a)  Persamaan kuadratik 4x  +  px = –p, dengan  p
                                                                                                 2
                      Persamaan kuadratik  kx  +  kx + 3 = 0, dengan  k   ialah pemalar, tidak mempunyai punca yang
                                            2
                      ialah pemalar, mempunyai dua punca sama. Cari       nyata. Cari julat bagi p.
                      nilai-nilai yang mungkin bagi k.                    The quadratic equation 4x  + px = –p, where p is a constant,
                                                                                             2
                      The quadratic equation kx  + kx + 3 = 0, where k is a constant,   has no real roots. Find the range of values of p.
                                         2
                      has two equal roots. Find the possible values of k.
                                                                             4x  + px = –p
                                                                                2
                         b  – 4ac = 0                                      4x  + px + p = 0
                          2
                                                                            2
                       k  – 4(k)(3) = 0
                       2
                                                                               2
                         k  – 12k = 0                                         b  – 4ac  0      +   –   +   p
                          2
                                                                            2
                        k(k – 12) = 0                                       p  – 4(4)(p)  0      0  16
                                                                              2
                               k = 0, k = 12                                 p  – 16p  0
                                                                             p(p – 16)  0
                                                                          ∴ 0  p  16
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         02 Hybrid PBD Mate Tambahan Tg4.indd   19                                                                29/09/2021   3:25 PM
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