Linear Algebra and Its Applications · Problem 1.4.13

Matrices and Gaussian Elimination — Gilbert Strang

Mathematics · matrix-notation-and-multiplication

Problem

By trial and error find examples of 2 by 2 matrices such that (a) A2=−IA^2 = -I, AA having only real entries. (b) B2=0B^2 = 0, although B≠0B \neq 0. (c) CD=−DCCD = -DC, not allowing the case CD=0CD = 0. (d) EF=0EF = 0, although no entries of EE or FF are zero.

Related theory

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