Finding a unit vector orthogonal to

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SUMMARY

The discussion focuses on finding a unit vector orthogonal to the vectors i + j and i + k using the properties of the dot product, despite the common approach being the cross product. The user contemplates using the formula A·B = |A||B| cos(θ) to derive a unit vector B that is perpendicular to the displacement vector of the given vectors. The assumption that θ should be 90 degrees is correct, as this indicates orthogonality. The user seeks clarification on whether their approach aligns with the principles of the dot product.

PREREQUISITES
  • Understanding of vector operations, specifically dot products
  • Familiarity with unit vectors and their properties
  • Knowledge of vector notation and representation in three-dimensional space
  • Basic trigonometry, particularly the concept of angles in relation to vector orthogonality
NEXT STEPS
  • Study the properties of dot products in vector mathematics
  • Learn how to derive unit vectors from given vectors
  • Explore the relationship between dot products and angles in vector spaces
  • Review examples of finding orthogonal vectors using both dot and cross products
USEFUL FOR

Students studying linear algebra, particularly those focusing on vector mathematics, as well as educators seeking to clarify the distinction between dot and cross products in vector analysis.

tnutty
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Homework Statement



Find a unit vector that is orthogonal to both i + j and i + k.

I know I can solve this using the cross product of the two. But This chapter is about
dot product and not cross product.

I am not sure how I could go about solving this problem using the properties of a dot product.

This is just a review, in test I would use the cross product.
 
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Thinking about this, I think I could use this formula :

A*B = |A||B| cos(theta);

=

B / |B| = |A|cos(theta) / A

Where A is the displacement vector from the given vector, and theta should be 90 deg.

Thus I would find a unit vector, B, perpendicular to the displacement vector of the
given vectors, which is parallel to Each of the 2 given vector.

Is this assumption correct?
 

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