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Unit 7: Limits




          We denote it by writing                                                               Notes
                                            or

          Similarly, if f(x) approaches the limit l , as x approaches ‘a’ from right we say, that the right hand
                                        2
          limit of f(x) as x   a is l .
                             2
          We denote it by writing
                                            or


          Working Rules
           Finding the right hand limit i.e.,   Finding the left hand limit, i.e.,



           Put      x = a+h                 Put      x=a – h
           Find                             Find


          Limits of a function Y = f(x) at x = a

                 Example: Find      where  f(x) = x  + 5x +3
                                                2
          Here                   =


                                 =

                                 =  1 + 5 + 3 = 9                                  ....(i)
          and                    =

                                 =


                                 =  1 + 5 + 3 = 9                                 ....(ii)
          From (i) and (ii),    =


                 Example: Evaluate:

          Here                   =



                                 =


                                 =       (as h>0, so|h|= h)

                                 =  1                                             ...(iii)

          and                    =








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