Page 47 - Pra U STPM 2022 Penggal 2 - Mathematics
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Mathematics Semester 2  STPM  Answers
                                                                                            2t
                                                                        2
                                                                   (c)  –3t (t – 1) 2  (d)  2
                                              2
                                          4
                  3.   2(2 – x)      4.   –3x  + 6x  + 8x                                 3t  + 1
                                          3
                                              2 2
                      (x + 2) 3          (x  + 2x )               2.  (a)  –cot q      (b)  –tan q
                  5.   2x cos x – sin x     6.   (ln x) – 1       3.  1
                        2x  x           (ln x) 2                  4.   cos t
                                                                      t
                                                                     e
                                        x
                  7.   1             8.   e  (x – 2)              5.  (0, 2), (0, –2)
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                    1 + cos x           (x – 1) 2                 9.  (2, 2), (2, –2)
                     2
                  9.  sec  x        10.  –cosec x
                                           2
                  11.  sec x tan x   12.  –cosec x cot x        Exercise 2.9
                                          x
                  13.   2           14.   e                       1.  (a)  2  1        (b)  34
                    1 – sin 2x         (2 + e )                    (c)  2              (d)  –1
                                           x 2
                                                                       4
                  15.   1                                             1
                                                                   1
                     x (1 –  x ) 2                                2.  –2,   2 2
                Exercise 2.6                                      3.  (a)  –  10       (b)  –  3
                                                                       13
                                                                                           4
                  1.  3e 3x          2.  2x e x 2                 4.  (a)  (3, –5)     (b)  (2, –8)
                  3.   2             4.  6(x + 1) 5                (c)  (0, –8)
                    x – 1
                                                                        π
                                                                           2
                                                                   1
                         3
                  5.  36x  (2x  + 1)   5  6.   8x                 5.  2n π +   , 1
                      2
                                        2
                                        x  + 1                          2
                                             –2
                  7.  2 sin x cos x   8.  – (x + 1)             Exercise 2.10
                                               π
                       2
                  9.  2x e (x  + 3)    10.  3 cos (3x +  )        1.  Increase for x . 3,
                                               4                     decrease for x , 3
                         2
                  11.  4x sin (x  + 1) cos (x  + 1)
                                  2
                  12.  2 cot 2x     13.  –(e  + e )(e  – e )      2.  Increase for x . 4,
                                                  –x –2
                                               x
                                         x
                                            –x
                                                                    decrease for x , 4

                                                 2
                  14.  –cosec x     15.  – 4x sin (2 + 2x )
                                                                  3.  Increase for x , –1,
                  16.   (2x – 3)(43 – 6x)     17.   –sin x           decrease for x . –1
                       (3x + 4) 4       1 + cos x                 4.  Increase for x , –2 and x . 2,
                                           2
                  18.   x           19.   2 sec 2x                   decrease for –2 , x , 0 and 0 , x , 2
                    1 + x 2             tan 2x
                                         4
                  20.   2x + 5      21.  tan x                  Exercise 2.11
                       2
                     2 3)                                       1.  –  , –  25   2
                      (x  + 5x +
                                                                     1
                                                                   1
                  24.  –   1  3     25.  –1                         1   2  14   4
                       2 1  1  π – 1 2 — 2                        2.   1  3  , –  27 2 , (3, –10)
                       2
                                                                  3.  (1, 0)
                Exercise 2.7                                      4.  (–2, 9)
                  1.  (a)  x + y  dy    = 0                       5.  (–1, –2), (1, 2)
                          dx
                   (b)  8x + 18y   dy    = 13                     6.  (2, 108), (0, 0), (5, 0)
                             dx                                     1    3
                   (c)  2x + y + (x + 2y)   dy    = 0             7.   1  4   ln  , 12 2
                                                                        2
                                   dx
                               dy                                   π   π     5π   5π
                   (d)  x  + (y  – 3)    = 0                      8.   1   ,   +  3 ), (    ,    –  3     2
                           2
                       2
                               dx                                   6  6      6  6
                        2
                   (e)  3x  + y + (2xy – 5x)  dy    = 5y            — 1 2  1
                           2
                                                                   1
                                     dx
                          2   3                                   9.  e ,   2e 2
                  2.  (a)   2y  – 2xy        (b)  cot x cot y       1
                        2 2
                       3x y  – 4xy – 3                            10.   1  2   ln 2, 2 2     2
                   (c)   x             (d)  2x + 5y + 2
                       y                  2y – 5x + 3           Exercise 2.12
                   (e)   sin 2x   –   cos 2x   – 3y               1.  (a)  (0, 0) maximum,  1  2   –4   2  minimum
                                                                                   ,
                        3  3x
                       x e    x e                                                 3 27
                               2  3x
                  6.  1                                            (b)  (2, 10) point of inflexion
                  7.  3                                            (c)  (2, 32) maximum, (6, 0) minimum
                  8.  –  1                                         (d)  (–1, –1) minimum, (0, 0) point of inflexion
                     3                                            2.  (3, 9)
                Exercise 2.8                                      3.  (a)  (0, 0)      (b)  (2, –11)
                                            2
                  1.  (a)   1          (b)  3(t  + 1)              (c)  (–1, –25), (3, –173)   (d)  (2, 0), (1, –1)
                       t                     2t
                                                                                                       197
         Ans STPM Math T Term2.indd   197                                                              28/01/2022   5:52 PM
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