A diagonal matrix whose diagonal elements all contain the same scalar 
.
A scalar matrix is therefore equivalent to 
, where 
is the identity matrix.
Scalar Matrix
See also
Diagonal Matrix, Identity Matrix, ScalarExplore with Wolfram|Alpha
References
Ayres, F. Jr. Schaum's Outline of Theory and Problems of Matrices. New York: Schaum, p. 10, 1962.Referenced on Wolfram|Alpha
Scalar MatrixCite this as:
Weisstein, Eric W. "Scalar Matrix." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/ScalarMatrix.html