Proving Perpendicularity: Solving Vectors Question | Homework Help

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SUMMARY

The discussion centers on proving that the sum of two linearly independent vectors of equal magnitude is perpendicular to their difference. The vectors are denoted as u and v, leading to the equation (u + v) · (u - v) = 0. This equation confirms the perpendicularity condition, as the scalar product must equal zero. The importance of linear independence in this context is emphasized, as it ensures that the vectors are not collinear.

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  • Understanding of vector operations, specifically addition and subtraction.
  • Familiarity with the concept of linear independence in vector spaces.
  • Knowledge of the scalar product (dot product) and its geometric interpretation.
  • Basic proficiency in algebraic manipulation of equations.
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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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