Page 23 - 102math-wb-w3-(analytic geometry)_Neat
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WORKBOOK






                 A)  Intersecting Lines:

                   If    a  b  , then the lines  and  are intersecting at a  point which is called intersection point of
                     d   e
                   and  .



                  That is, the system of equations ++ =  ++ =  has a unique solution
                  Ex: Are the following pairs of lines intersecting? If so, find the coordinates of intersection
                  point.

                  a) x+y = 0        x−y = 4           b) x= 3        x−2y = 5                           c) 3x+2y = 1
                  2x−3y = −2

                  Ex: For which value of k , the following system equation does not have a unique solution ?
                  (k−2)x+3y = 1              3x−y = 7





                   B)  Parallel Lines :

                   If   a  b  c  , then the lines  and  are parallel ( //  ) ,
                     d   e  f
                  which means that  and  are NOT intersecting.


                  If  //  , the system of equations ax+by+c = 0 dx+ey+f = 0 has no

                  solution.

                  Note that, two lines are parallel If and only If their slopes are equal.

                  That is ,  //  ⇔  =  .



                  This means that, any two nonvertical parallel lines have equal slopes.










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