Relasi dan Fungsi

Share on :

Tweet

Suatu  fungsi ditentukan dengan rumus   f(x) = ax + b. 

Jika  f(2) = 13 dan f(5) = 22, tentukanlah persamaan tersebut :

Penyelesaian :

                             f(2) = 13                 f(5) = 22

                        2a + b = 13                  5a + b = 22

                                b = 13 – 2a          5a + (13 – 2a) = 22

                                                               5a + 13 – 2a = 22

                                                                5a – 2a + 13 = 22

                                                                 3a              = 22 – 13

                                                                 3a                 = 9

                                                                                  a = 3

                                b = 13 – 2a

                                    = 13 – 2.3

                                 b = 7       maka f(x) = 3x + 7