subexpressions (OT: math)

[Peter Otten]

Stebanoid at gmail.com wrote:

> sine is a dimensionless value.
> if we expand sine in taylor series sin(x) = x - (x^3)/6 + (x^5)/120
> etc.
> you can see that sin can be dimensionless only if x is dimensionless
> too.

With y = x^2 = 1/3 pi^2 - 4(cos x - cos(2x)/2^2 + cos(3x)/3^2 - ...)

area is dimensionless, too, I suppose.
 
> I am a professional physicist and a know about what I talk

Then you can kindly point me to the flaw in that logic :-)

Peter