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Five math non-word problems to commemorate Pi Day 2019
Remember just a few years ago, when there was always the possibility that March 14 could be a slow news day? Then Pi Day could be relied upon to fill some columns on the paper and kill a couple of minutes on the nightly news.
Today, March 14, 2019, is sure to abound with news, a lot of them crazy. But hopefully the newspapers and nightly news will still at least have fleeting mentions of Pi Day today.
As you know, mathematicians use π (the Greek lowercase letter pi) to represent the ratio of a circle’s circumference to its diameter, among other things. This number has a value of approximately 3.14159265358979.
There are people who say we should celebrate Tau Day instead. That would be on June 28.
Some mathematicians use τ (the Greek lowercase letter tau) to represent the ratio of a circle’s circumference to its radius (rather than to its diameter). And of course mathematicians also use τ to mean other things.
In the context of circle geometry, we have τ = 2π, roughly 6.2831853. A consequence of this is that Euler’s identity is then e to the power of i times τ is 1, rather than e to the power of i times π being −1 (and then some people feel the need to add 1 to that in order to get 0 in there, as if −1 was an unimportant number). I personally like…