Plea bargains. Bench trials. Pleading the Fifth. Law students—and anyone who has seen Law and Order—will recognize these as familiar features of the US criminal justice system. But, as Emma Kaufman ...

Learn how to write the explicit formula for the nth term of an arithmetic sequence. A sequence is a list of numbers/values ...

Tie a trefoil knot in a piece of string, seal the ends together, and try to wiggle it free without cutting. In three-dimensional space, the knot holds firm. Add a fourth spatial dimension, however, ...