For Kenneth Schilling's 'Derivative Sign Patterns in Two Dimensions" (March) Web Addendum (pdf).
For Timothy Jones' 'Euler's Identity, Leibniz Tables and the Irrationality of Pi' (November): End Notes (pdf)
For Stephen M. Walk's The Intermediate Value Theorem is NOT Obvious—and I AM Going to Prove It to You (September): Proofs Leading to the Intermediate Value Theorem (pdf)
For Michael A. Jones' Chutes and Ladders for the Impatient (January), MAPLE file.
For Richard Kreminski's, Taylor’s theorem: the elusive c is not so elusive (May):
Proofs of Theorems 2 and 3, plus other materials(pdf)
For Rick Mabry’s The Hardest Straight-in Pool Shot (January), proofs of all nine FACTS, written on napkins. Separate napkins (pdfs):
All the napkins in one wad: Facts 1-9
For Barry Cox and Stan Wagon’s Mechanical Circle-Squaring (September, pp 238-247), Mathematica generated simulations:
Geneva Drive Maltese Cross
Drilling a Square Hole
Drilling a Square Hole (Three Dimensions)
Drilling a Hexagonal Hole