Unlock the power of Finite Element Methods (FEM) with this comprehensive guide from The Bookish Owl. Designed for engineers and scientists, this self-tutorial provides a robust theoretical foundation and practical problem-solving techniques. It uniquely blends a concise overview of FEM mathematics with extensive, problem-driven examples, fostering active learning. Explore diverse exercises and immediate solutions that demystify functional analysis in engineering applications. This enlarged English edition enhances understanding with a new chapter on approximation steps from differential equations and an introduction to tensor calculus using distribution theory, making it an invaluable resource for mastering FEM.