Page 81 - Intro to Tensor Calculus
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                                           Figure 1.3-10. Oblate spheroidal coordinates






























                                              Figure 1.3-11. Toroidal coordinates


                                                           i
               EXAMPLE 1.3-4. Show the Kronecker delta δ is a mixed second order tensor.
                                                           j
                                                                   i
                                                                        i
               Solution: Assume we have a coordinate transformation x = x (x),i =1,... ,N of the form (1.2.30) and
                                                                       i
                                                                              i
               possessing an inverse transformation of the form (1.2.32). Let δ and δ denote the Kronecker delta in the
                                                                       j      j
               barred and unbarred system of coordinates. By definition the Kronecker delta is defined

                                                   i   i    0,    if  i 6= j
                                                  δ = δ =                 .
                                                   j
                                                       j
                                                            1,    if  i = j
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