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Mnemonic For Remembering Formulas for Sin, Cos, Tan

Date: 05/15/98 at 19:00:31
From: Don Burd
Subject: Trigonometric ratios.

When I was in high school, my trigonometry teacher told us a story 
that helped us remember the formulas for sin, cos, and tan. I have 
forgotten the story. The punchline of the story was something about 
the name Chief Sohcahtoa (SOH CAH TOA).

Please help me if you can. I would like to know the story so I can 
use it in my own classroom. Thank you.

Don Burd

Date: 05/18/98 at 12:01:03
From: Doctor Pat
Subject: Re: Trigonometric ratios.


Here is the version I tell my students. It is sort of an accumulation 
of add-ons that have come from year to year.

A young brave, frustrated by his inability to understand the geometric 
constructions of his tribe's battle dress, kicked out in anger against 
a stone and crushed his big toe. Fortunately, he learned from this 
experience, and began to use study and concentration to solve his 
problems rather than violence. This was especially effective in his 
study of math, and he went on to become the wisest man of his tribe.  
He studied many aspects of trigonometry; and even today we remember 
many of the functions by his name. When he became an adult, the tribal 
priest gave him a name that reflected his special nature -- one that 
reminded them of his great discoveries and of the event which 
changed his life. Because he was troubled throughout his life by the 
problematic foot, he was constantly at the edge of the river, soaking 
his aches in the cooling waters. For that behavior, he was named Chief 
Soh Cah Toa.  

OK, it's corny. Kids will hoot and boo, . . . and remember it.

Feel free to embellish this with your own personality, and eventually 
it becomes YOUR story. Keep at it. These kinds of stories are part of 
the culture of mathematics that give it some of its richness.  

-Doctor Pat, The Math Forum
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Associated Topics:
High School Trigonometry

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