Page 29 - Mathematics_Form_3
P. 29

Relations


               Exercise 1.7                            5.    R  =  {(x, y ):  y  =  2x + 1}  .

               In questions 1 to 3, find the inverse of   6.    R  =  {(x, y ):  2y − 1  =  4x}  .
               each of the given relations.            7.   R  =   {(x, y ):  y  =  x     }  .
                                                                             2
               1.  R is the set of all pairs of coordinate
          FOR ONLINE READING ONLY
                                                       8.   R  =  {(x, y ):  y  <  0}  .
                   points in the xy - plane.
                                                       9.   R  =  {(x, y ):  3x  >  y} .
               2.  R is the set of all ordered pairs  (x, y)
                   of real numbers where y is the cube   10.  R  =  {(x, y ):  2x + 5  <  y}  .
                   root of  x .                        11.  R  =   (x, y ):  y  =    _ }
                                                                              2
                                                                                       .
                                                                {
                                                                            x + 5
               3.  R is the set of all pairs of coordinate   12.  R  =   {(x, y ):  y  =  3  x     − 1} .
                                                                               2
                   points in the xy-plane which lie
                   below the line  y = 4 .
               4.  Study the relation R shown in the  Graphs of inverse relations
                   following figure and answer the    Consider the relation

                   subsequent questions.                R  =    {(x, y )  : y  >  x} .  Its inverse is given
                                R                     by   R       =   {(x, y )  : y  <  x} .  In this case, R
                                                          −1
                                                      is the relation “greater than” for all real
                     a                   p            numbers, while   R       is the relation “less
                                                                       −1
                     b                   q            than” for all real numbers.
                     c                   r            The graphs of  R  =   {(x, y )  : y  >  x}   and
                                                       −1
                     d                   s            R       =   {(x, y )  : y  <  x}   are shown in the
                     e                                shaded regions in Figure 1.9 and Figure
                                                      1.10, respectively. y 4

      Mathematics for Secondary Schools  (b)  Make a list of all ordered pairs   -5-4 -3 -2 -1 0 3 2 1  1  2  y = x 4  x
                   (a)  Make a drawing to show the
                                        −1
                       inverse relation   R      .


                                     −1
                       belonging to   R      .
                   (c)  Which set is the domain of   R      ?
                                                 −1
                                                                                  3
                                                                       -1
                   (d)  Which set is the range of   R      ?
                                                 −1
                                                                       -2
               In questions 5 to 12, find:
                                                                       -3
                                                                       -4
                   (a)  The inverse of a relation.
                                                                       -5
                   (b)  The domain and range of the
                       inverse of a relation.            Figure 1.9:  Graph of the relation
                                                                    R =  ( { x, y ) y >:  x }




                                                    22                 Student\s Book Form Three



                                                                                          18/09/2025   09:58:45
     MATHEMATIC F3 SB.indd   22
     MATHEMATIC F3 SB.indd   22                                                           18/09/2025   09:58:45
   24   25   26   27   28   29   30   31   32   33   34