Page 1 - mind map - sign convention rules of sph lens
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Sign convention

                                                       rules








                                                                         Lens formula:-
                   All distances parallel to the principal axis are
                      measured from the center of the lens.                 1/v-1/u=1/f
                  All the distances measured to the right of the
                 origin (along + x-axis) are taken as positive while   Magnification=v/u
                those measured to the left of the origin (along - x-
                           axis) are taken as negative.

                 Distances measured perpendicular to and above
                  the principal axis (along + y-axis) are taken as
                                   positive.
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