Dot Product Rules Multiple choice

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The discussion centers on a homework problem regarding the rules of dot product multiplication. The user has identified two solutions they believe are valid and two they think are invalid, specifically favoring options C and D. However, they express uncertainty about their reasoning, as their selections were incorrect. A hint is provided, emphasizing the need to understand whether the dot product results in a vector or scalar quantity. The conversation highlights the importance of justifying answers with solid reasoning rather than intuition alone.
Lothar
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Homework Statement


See the image
http://tinypic.com/r/33z6vz5/7

Homework Equations


The rules of dot product multiplication.


The Attempt at a Solution


I've determined that 2 of the solutions are valid, while two of the choices are invalid. I thought C and D looked correct, making A and B incorrect. Unfortunately it wasn't so. I'm down to my last submission and I really don't know what I'm doing wrong.

Thanks you
 
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Why do you think the answers are valid or invalid? You need reasons better than an answer "looked correct."

Hint: What type of quantity, vector or scalar, is the dot product of two vectors?
 

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