Page 66 - Math SL HB Sem 2
P. 66

Kolej MARA Seremban                                         Mathematics  IB High Level
                                                                                         Core : Yectors

                            b                                  b


                                                                      a
                    a       a+b                        a      b;-a

                                                             b

                 From the right figure, it is evident that a + b = b + a, and the sum coincides with the
                 diagonal  of the parallelogram when the two vectors  are positioned so they have the same
                 initial point.

                 Subtraction  Of Vectors

                 If a and b are any two vectors,  then the dffirence of b from a is defined by
                     a-b:a+(-b).

                 Toobtainthedifferencea-bwithoutconstructing-b,positionaandbsotheirinitial
                 point coincide.  The vector from the terminal  point of b to the terminal point of a is then the
                         -
                 vector a  b.


                                                             a
                       a-        a                                    a-b


                       -b          b                             b


                 Scalar Multiplication Of Vectors





                                                Ifa is a vector  and 1" is a nonzero  real number ( scalar  ),
                   a                            ther, the  product  Xa is a vector whose length is I ?" I ti-"s
                                      I
                       2a           - -a        the length of a and the direction is the same as a if 1" > 0
                                      2
                                                and opposite to that ofa if l, < 0.



                  Position Vector
                            A
                                                 --t
                                                OA is called the position vector of A relative to the origin.


                            a                   Vectors  such as a which  is not related to a fixed position
                                                are known as  free  vectors.
                  o
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