# Transformations that preserves the vector angles?

• July 5th 2013, 02:25 AM
Stormey
Transformations that preserves the vector angles?
I read somewhere that normal transformations (hermitian, unitary, orthogonal, etc...) preserves the angles between vectors.
but transformation is a function that operates on one vector, not two ( $T(v)=w$), so what angle exactly are we talking about here?
• July 5th 2013, 02:48 AM
chiro
Re: Transformations that preserves the vector angles?
Hey Stormey.

I'm not certain but I'm thinking that it means that <Tu,Tv>/|Tu|*|Tv| = <u,v>/|u||v| where <.,.> is an inner product and |.| is a norm = SQRT(<.,.>)
• July 5th 2013, 01:17 PM
Stormey
Re: Transformations that preserves the vector angles?
Hi chiro.
thanks for the help.
• July 5th 2013, 05:14 PM
HallsofIvy
Re: Transformations that preserves the vector angles?
Yes. Saying that "T preserves angles" means that the angle between Tu and Tv is the same as the angle between u and v.