[BlindMath] Interesting way to present Trig to the blind.

[Ray McAllister]

Hi, how are you?  So I’m noticing something.  It’s always hard to show trig
identity proofs to the blind, as many of them require big diagrams.  

In complex analysis I’m learning how to use Euler’s Formula to convert
cosine and sine to exponential functions (powers of E) and when you do that,
the proofs are effortless.  It’s easy to see what happens when writing
cos(a+b) when you write the whole thing out as powers of E.  Cosine is ½
(e^(I x) + e^(-I x)) 

Sine is 

-i/2 * (e^(I x) – e^(-I x)) 

 

I’m wondering if anyone has thought about writing some sort of article for
the blind, especially, explaining this.  We don’t have to tell everything
about complex analysis. A few things, like the basics of E, and the Taylor
series for E, sine, and cosine, and those are all things anyone can test
quickly in a computer or calculator.  A little about e^(pi i) = -1, and
then, show how to multiply these expressions.  Algebra II does usually have
a brief unit on complex numbers, and most of what you learn there is all you
need for this.  

I can see some of the trig proofs a lot more easily this way, and I wonder
if other blind people can as well.  

 

Ray.