Reference no: EM132414001
Questions -
Q1. Let A be a skew-symmetric n x n-matrix with entries in R, i.e. AT = -A.
(a) Prove that uTAu = 0 for every u ∈ Rn.
(b) Prove that In + A is an invertible matrix.
(c) Give an example of a skew-symmetric 2 x 2-matrix B with entries in C for which I2 + B is not invertible.
Q2. Let two vectors x→ = (x1, x2, ..., xn) and y→ = (y1, y2, ...., yn).
a) Provide definition of orthogonality.
b) Prove that if x→ and y→ are mutually orthogonal, then they are linearly independent.
Q3. If G is a group and H is a subgroup of G, then H is a normal subgroup of G if ghg-1 ∈ H for all g from the set of generators of G and for all h from the set of generators of H.