Albert Einstein's general theory of relativity (E=mc2), is a central theory in modern physics with implications on our insight into everything from black holes to the expansion of the universe. But how did Einstein come up with it? And what has happened to it since then? The Secret Life of Equations is not a mathematics book but a map by which readers can discover equations from a different perspective. Selected from geometry, technology, science, chance and mathematics, the 50 equations are explored by way of their history. Why were they needed? How were they developed? What is their value today? The equations are presented as follows: Concise, understandable text highlighted with clever illustrations. Visual and textual descriptions of the equations' components, for ultimate clarity. "What's It About" fictional scenarios explain the original problems or theories in want of a solution or proof. "What's It Good For?" descriptions tell how the equations proved theories and how they are used today. In uncomplicated text, the book follows the evolution of each equation, bringing to life the brilliant minds and unique characters that starred in the story and how their achievements advanced modern theory. It points out the faults and problems that arose and explains how the equations are fundamental to our understanding of the world, not to mention the unfathomable universe. The Secret Life of Equations will enlighten and entertain in equal measure. It is excellent for readers interested in mathematics history and for students that would benefit from the allegorical explanations.