Roger B NelsenRoger B. Nelsen (BA DePauw University, Ph.D. Duke University) is Professor Emeritus of Mathematics at Lewis and Clark College. Roger has been an AP Calculus Reader for many years and has authored or co-authored four books for the MAA: Proofs Without ords: Exercises in Visual Thinking (1993); Proofs Without Words II: More Exercises in Visual Thinking (2000); Math Made Visual: Creating Images for Understanding Mathematics (with Claudi Alsina, 2006); and When Less Is More: Visualizing Basic Inequalities (with Claudi Alsina, 2009). Read More Read Less