16.-Linear-Algebra-by-Kenneth-Hoffman · Problem 3.5.13
Linear Transformations
Mathematics — Linear Algebra · product-of-linear-functionals
Problem
Let F be a subfield of the field of complex numbers and let V be any vector space over F. Suppose that f and g are linear functionals on V such that the function h defined by h(α)=f(α)g(α) is also a linear functional on V. Prove that either f=0 or g=0.