Author Archive
How do I prove that 5 divides x^5 – x? The joys of modular arithmetic
Posted by: Gary Ernest Davis on: February 11, 2010
On Physics Forums , ninjagod123 asked: “How do I prove that 5 divides ??” In this question, the variable “” should be thought of as restricted to integer values – in fact positive integer values – since divisibility for fractions or real numbers in general is trivial. So another way to ask the question is: […]
5" of snow: is that a lot of snow?
Posted by: Gary Ernest Davis on: February 10, 2010
It’s snowing heavily here in Dartmouth, Massachusetts. Forecasts are anything from 5″ – 12″ of snow before it eases overnight. Is 5″ of snow a lot of snow? Let me tell you, when I’m shovelling it, it seems like a lot! Could we compare 5″ of snow with something else – like water, for example. […]
