BG B.

# dot product

|a|=3  |b|=5. find the value of β if a+βb and a-βb are perpendicular.

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Philip P.

Philip,

Kirill answered the question 3 hours before you did, with the same method, and got the same answer.  What's up with your over-posting his answer?  It looks and feels like grandstanding on your part.
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09/02/14

Phillip R.

I have observed that often more than one tutor gives the same answer by the exact same method hours or even days apart. krill didn't explain why the dot product is zero although I'm sure he knows so I pointed out that the angle is 90 and cos 90 is zero and based on the dot product formula, it is why it has a value zero. Other than that I completed the question for completeness sake and did not intend to steal Krill's thunder But given his approach was best I didn't want to show the student anything different to create confusion. Having said that which defends what I did and in my opinion is valid, your motivation for objecting is suspect. Do you guys have some sort of club that'a existed for years and it irks you that there is someone new answering a lot of math questions. My advice is mind your business. Do you make the rules for Wyzant? I didn't think so. Why don't you try assuming positive intent on my part. I'm trying to help the students if I can. Hopefully I don't make too many mistakes. I have no desire to show off as you suggest. Not at my age. And I don't do it to attract clients and their money because I don't need the money. In summary, you're comments are not welcome and I will tell Wyzant as much.
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09/02/14

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