Recent content by Teggles

Awesome. I managed to write a full proof that it would equal 0. I'm fairly glad you omitted some of the reasoning/detail because it actually made me think about and understand each step for myself. Thanks for your help! Still haven't worked out what "geometric fact" the question wants, but I'll...

Well... (u - v) . (u + v) = |u - v| |u + v| cos θ Of course, I don't know |u - v| or |u + v|, only that |u| and |v| are the same. I don't know how this bit of information is meant to be used. If the vectors are perpendicular, θ will be 90 degrees, and so dot product will be 0. Is my aim to...

"If u and v are any two vectors of the same length, use the dot product to show that u + v is perpendicular to u − v. What fact from geometry is does this represent." This is basically the last question in an assignment on vectors (first year university, linear algebra). The questions all focus...