Page 159 - ADVANCED MATH F.5
P. 159

Form Five                                                            Form Five



               (c)   dy  = 18x (3x −  2                    (d)    dy  =  ( xx +  ) 5  −  1 2
                                                               2
                                2
                    dx               ) 4              dx
                                             1
            3.  (a)    ft ′ () = (t −  3 )(t −  2  6t +  ) 7  −  2
         FOR ONLINE READING ONLY
               (b)    ft ′ ( ) = −  21 (3 t−  )
                                     20
                           3           − 3
               (c)  gz ′ () =  z 2 (3 z 3 )
                                  −
                                        2
                           2
                                  3
                                 −
                        2 ⎛   1 ⎞⎛      1 ⎞
                                  5
               (d)  z′ =  ⎜ x +  ⎟⎜ 1−   2 ⎟
                        5 ⎝    x ⎠⎝     x ⎠
               (e)  y′ =  2.9 t −  (  3  t  ) ⎜  1.9  ⎛  3t −  2  1 ⎞  ⎟
                                      ⎝     2 t ⎠


                               8t +  3  9t −  2  5
            5.  (a)   f  ()t ′  = −          4            (b)  f ′ ( 1) 0.06189−=
                           3 3  ( 2t +  4  3t −  3  5t +  ) 6

                       4
                      r + 1                                1
            6.  r′ =                          8.  x′ =           2
                    r 2  r − 1                         3  ⎛   2 ⎞  3
                         4
                                                     3u 2  ⎜  1−  ⎟
                                                15       ⎝    u ⎠
                                4
            7.  θ    10 (4 2θ′ = −  −  )      9.  16


          Differentiation of implicit functions

          Teaching steps
             1.  Use  Think-Ink-Pair-Share strategy to recognize an implicit
                 function. Assist students to write an implicit function in terms
                 of both dependent and independent variables.

             2.  Guide students through discussions to use the product rule and
                 chain rule to deduce the implicit differentiation formula of the
                        d                   dy
                                                       n
                 form,     ( xy n ) =  nxy n−  1  +  mx m−  1 y .  Allow students to
                             m
                                      m
                        dx                  dx
                                  153
                                             Mathematics for Advanced Secondary Schools


                                                                        30/06/2024   18:02:38
   ADVANCED MATH F.5 TG CHAPTERS.indd   153                             30/06/2024   18:02:38
   ADVANCED MATH F.5 TG CHAPTERS.indd   153
   154   155   156   157   158   159   160   161   162   163   164