# subexpressions (OT: math)

Stebanoid at gmail.com Stebanoid at gmail.com
Sun Jun 3 20:07:25 CEST 2007

```On 3    , 21:43, Gary Herron <gher... at islandtraining.com> wrote:
> Steban... at gmail.com wrote:
>
> > angle is dimensionless unit.
>
> Of course not!  Angles have units, commonly either degrees or radians.
>
> However, sines and cosines, being ratios of two lengths, are unit-less.> To understand it: sin() can't have dimensioned argument. It is can't
> > to be - sin(meters)
>
> No it's sin(radians) or sin(degrees).> it is difficult to invent what is a "sqrt from a angle" but it can be.
>
> I don't know of any name for the units of "sqrt of angle", but that
> doesn't invalidate the claim that the value *is* a dimensioned
> quantity.  In lieu of a name, we'd have to label such a quantity as
> "sqrt of degrees" or "sqrt of radians".      After all, we do the same
> thing for measures of area.  We have some units of area like "acre", but
> usually we label areas with units like  "meters squared" or "square
> meters".    That's really no stranger than labeling a quantity as "sqrt
> of degrees".
>
> Gary Herron, PhD.
> Department of Computer Science
> DigiPen Institute of Technology

angle is a ratio of two length and dimensionless.
http://en.wikipedia.org/wiki/Angle#Units_of_measure_for_angles

only dimensionless values can be a argument of a sine and exponent!
Are you discordant?

```