16.-Linear-Algebra-by-Kenneth-Hoffman · Problem 3.6.1
Linear Transformations
Mathematics — Linear Algebra · annihilator-hyperplane
Problem
Let n be a positive integer and F a field. Let W be the set of all vectors (x1,…,xn) in Fn such that x1+⋯+xn=0.
(a) Prove that W0 consists of all linear functionals f of the form
f(x1,…,xn)=cj=1∑nxj.
(b) Show that the dual space W∗ of W can be `naturally' identified with the linear functionals
f(x1,…,xn)=c1x1+⋯+cnxn
on Fn which satisfy c1+⋯+cn=0.