The discussion revolves around finding the angle between two vectors, specifically the vectors [-1, 1, 2] and [2, 1, -1]. The problem involves using the cosine formula related to the dot product and the magnitudes of the vectors.
There is ongoing clarification regarding the dot product and its properties. Some participants have identified errors in calculations, while others are exploring how to derive the angle from the cosine value. The discussion reflects a mix of attempts to correct misunderstandings and to verify calculations.
Participants mention careless errors in calculations and the need for careful interpretation of mathematical terms, indicating a focus on precision in mathematical reasoning.
magicarpet512 said:Your <u,v> must be a vector, not a scaler.
magicarpet512 said:Your <u,v> must be a vector, not a scaler.
spamiam said:<br /> \cos\theta = \frac{-3}{\sqrt{6}\sqrt{6}} = ?<br />
:P
spamiam said:No, \langle \cdot, \cdot \rangle is the inner product, the same thing as the dot product.
\langle \vec{u}, \vec{v} \rangle is the same as \vec{u} \cdot \vec{v}.
magicarpet512 said:Your <u,v> must be a vector, not a scaler.
magicarpet512 said:sorry, i didnt mean to say that!
As spamiam is hinting, how do you get \theta?