16.-Linear-Algebra-by-Kenneth-Hoffman · Problem 2.3.11
Vector Spaces
Mathematics — Linear Algebra · traceless-matrix-space
Problem
Let V be the set of all 2×2 matrices A with complex entries which satisfy A11+A22=0.
(a) Show that V is a vector space over the field of real numbers, with the usual operations of matrix addition and multiplication of a matrix by a scalar.
(b) Find a basis for this vector space.
(c) Let W be the set of all matrices A in V such that A21=−A12 (the bar denotes complex conjugation). Prove that W is a subspace of V and find a basis for W.