This textbook introduces functional analysis on an elementary level without presupposing a background in real analysis like metric spaces or Lebesgue integration theory. Haase focuses on notions and methods that are relevant in applied contexts, but says the material should also serve as a stepping stone towards more advanced texts in functional analysis. He helps students learn to view function/sequences as points in certain spaces abstracted from their internal structure, to recognize orthogonality and its fundamental role for series representations and distance minimization in Hilbert spaces, to use operators as a unified tool for producing solutions to a problem with varying initial data, and other matters. Annotation ©2014 Ringgold, Inc., Portland, OR (protoview.com)