Real functions as infinite-dimensional vectors

Real functions are vectors

Endomorphisms of infinite-dimensional vector spaces

Endomorphisms on real functions

Examples of linear operators on real functions

Eigenvalues and eigenvectors of infinite-dimensional vectors

Spectral theorem for infinite-dimensional vector spaces

Forms on infinite-dimensional vector spaces

Forms on real functions

Functionals

Hilbert space

Calculus of variations

Calculus of variations

Functional integration

Sort

Banach space