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INTEGRAL FUNGSI ALJABAR


                                                       1           3             1
                        4
                                                 5
                       4
                                                                           5
                                            4
                            5
            10.  ∫ 3   √2   − 1       = ∫    (2   − 1)4       =      1  (2   − 1)4 +1  +    =
                                                               2.5.(1+ )
                                                                     4
                   6           5
                         5
                    (2   − 1)4 +    (cara cepat).
                   25

                                                                           1
                      3                2      − 1          3       2      − +1        9   2     2
            11.  ∫ 3            = ∫ 3  (   + 1) 3      =      1   (   + 1) 3   +    =  (   + 1)3 +   
                      2
                    √   +1                            1.2.(1+(− ))                    4
                                                              3
                  (cara cepat).

                          3
                    (√  +3)
            12.  ∫               =
                      √  
                                          ′
                  Misal :    =  √   + 3  →    =   1   →        =  1   →      = 2√       
                                               2√           2√  
                          3
                    (√  +3)            3                     1           1          4
                                                                4
                                                     3
                  ∫              = ∫  2√        = ∫          =    +    =   (√   + 3) +   
                      √             √                        4           4

                           −2
                         1      1
            13.  ∫ (4 + )     ( )       =
                                  2
                                  1            1             1
                                        ′
                                                                            2
                  Misal :    = 4 +  →    = −      →    = −      →      = −        
                                                  2             2
                            −2                                                                    −1
                          1     1                1                                              1
                                                       2
                   ∫ (4 + )    ( )       = ∫    −2   . −         = − ∫    −2        =    −1  +    = (4 + )  +   
                                   2               2                                              

            14.  ∫   √2   − 1       =
                                                          1
                                                                             1
                                                              2
                                            2
                  Misal :    = √2   − 1 →    = 2   − 1 → (   + 1) =     → . 2        =       →         =     
                                                          2                  2
                                       1   2                  1  4   1  2       1   5   1  3
                  ∫   √2   − 1       = ∫ (   + 1).   .         = ∫    +          =      +    +    =
                                       2                      2      2          10      6
                  1          5   1         3
                    (2   − 1)2 + (2   − 1)2 +   
                  10             6
                  *Selain  menggunakan  cara  substitusi,  soal  ini  juga  bisa  diselesaikan  menggunakan  cara
                  integral parsial seperti soal no. 16

                                      2
                     2
                                                      2
                       +4  −1          −1+4             −1         4                      4  
            15.  ∫                = ∫             = ∫           + ∫          = ∫ 1      + ∫         =
                                       2
                       2
                                                      2
                                                                   2
                                                                                          2
                        −1               −1             −1           −1                     −1
                  ∫ 1      =    +   
                     4                 2     −1        4     2                   2
                  ∫           = ∫ 4   (   − 1)       =   ln(   − 1) +    = 2 ln(   − 1) +   
                     2
                       −1                             1.2
                     2
                       +4  −1
                                            2
                  ∫               =    + 2 ln(   − 1) +   
                       2
                        −1








                                                                                      ‘LEARNING IS FUN’  42
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