Final answer:
The dot product of vectors X and Y is proportional to cos(θ), where θ is the angle between X and Y. Therefore, X ⋅ Y bisects the angle between X and Y.
Step-by-step explanation:
In order to show that X ⋅ Y bisects the angle between X and Y, we need to show that the angle between X ⋅ Y and X is half the angle between X and Y. Let's denote θ as the angle between X and Y. The dot product of two vectors is defined as the product of their magnitudes and the cosine of the angle between them:
X ⋅ Y = |X||Y|cos(θ)
We also know that the lengths of vectors X and Y are the same, so |X| = |Y|. Substituting this into the equation gives:
X ⋅ Y = |X||X|cos(θ) = |X|^2cos(θ)
This shows that X ⋅ Y is proportional to cos(θ), which means that the angle between X ⋅ Y and X is equal to θ/2, proving that X ⋅ Y bisects the angle between X and Y.