Changes

:<math>\sum_{i=-\infty}^\infty c_i \delta_{ij} =c_j</math>.

:<math>\sum_{i=-\infty}^\infty c_i \delta_{ij} =c_j</math>.

The elements of the [[Identity_matrix|identity matrix]] can be seen as following Kronecker Delta (i.e, <math>(I)_{ij} = \delta_{ij}</math>). To see this, let <math>A</math> be an nxn matrix, <math>a_{ij}</math> be its elements and <math>I</math> be the nxn identity matrix. Then <math>A = AI</math>  so,

The elements of the [[identity matrix]] can be seen as following Kronecker Delta (i.e, <math>(I)_{ij} = \delta_{ij}</math>). To see this, let <math>A</math> be an nxn matrix, <math>a_{ij}</math> be its elements and <math>I</math> be the nxn identity matrix. Then <math>A = AI</math>  so,

:<math> a_{ij} = \sum_{k=0}^n a_{ik}(I)_{kj} = \sum_{k=0}^n a_{ik}\delta_{kj} = a_{ij}</math>

:<math> a_{ij} = \sum_{k=0}^n a_{ik}(I)_{kj} = \sum_{k=0}^n a_{ik}\delta_{kj} = a_{ij}</math>

where the definition of [[Matrix#Multiplication_of_matrices|matrix multiplication]] and the above property of summation was used.

where the definition of [[Matrix#Multiplication of matrices|matrix multiplication]] and the above property of summation was used.

The continuous analogue of Kronecker Delta is [[Dirac delta]].

The continuous analogue of Kronecker Delta is [[Dirac delta]].

==References==

==References==

Weisstein, Eric W. "Kronecker Delta." From MathWorld--A Wolfram Web Resource. http://mathworld.wolfram.com/KroneckerDelta.html

Weisstein, Eric W. "Kronecker Delta." From MathWorld—A Wolfram Web Resource. http://mathworld.wolfram.com/KroneckerDelta.html

[[Category:Mathematics]]

[[Category:Mathematics]]