Proving Perpendicularity: Solving Vectors Question | Homework Help

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To prove that the sum of two linearly independent vectors of equal magnitude is perpendicular to their difference, one must show that the scalar product of their sum and difference equals zero. Specifically, for vectors u and v, this means demonstrating that (u + v)·(u - v) = 0. The condition of linear independence implies that the vectors cannot be expressed as scalar multiples of each other, which is crucial for the proof. Clarification on the notation is necessary, as the initial mention of v1 and v2 does not directly relate to the vectors in question. Understanding these relationships is key to solving the problem effectively.
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Homework Statement


If two linearly independent vectors are of equal magnitude, prove that their sum is perpendicular to their difference.


Homework Equations


v1.v2 = 0


The Attempt at a Solution


This question doesn't seem that hard but it's really confused me.
Help is appreciated, thanks.
 
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Just write down the scalar product!
 
noahsdev said:

Homework Statement


If two linearly independent vectors are of equal magnitude, prove that their sum is perpendicular to their difference.


Homework Equations


v1.v2 = 0
This is a "relevant equation" only if you say what v1 and v2 are! In particular are you clear that v1 and v2 are NOT the "two linearly independent vectors" of the question? Call the two vectors u and v. Their sum is u+ v and their difference is u- v. So "their sum is perpendicular to their difference" means (u+ v).(u- v)= 0. What does the fact that they are linearly independent tell you?


The Attempt at a Solution


This question doesn't seem that hard but it's really confused me.
Help is appreciated, thanks.
 
noahsdev, per Physics Forums rules, you must show what you have tried when you post a question.
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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