Drawing a Collection Of vectors Satisfying Cross Products

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SUMMARY

The discussion focuses on solving the vector equation involving the cross product, specifically finding all position vectors \( c \) that satisfy the equation \( a \times b = a \times c \) given \( a = <1,2,3> \) and \( b = <1,-1,-1> \). The calculated cross product \( a \times b \) results in \( <1,4,-3> \). The user defines \( c = \) and sets up a system of equations: \( 1 = 2z - 3y \), \( 4 = 3x - z \), and \( -3 = y - 2x \). The discussion concludes that the solution for \( c \) is not unique, as any vector of the form \( c + k \cdot a \) (where \( k \) is a constant) will also satisfy the equation.

PREREQUISITES
  • Understanding of vector operations, specifically cross products.
  • Familiarity with solving systems of linear equations.
  • Knowledge of vector representation in three-dimensional space.
  • Basic algebraic manipulation skills.
NEXT STEPS
  • Explore the properties of cross products in vector algebra.
  • Learn techniques for solving systems of linear equations using methods such as substitution and elimination.
  • Study the geometric interpretation of vector equations in three-dimensional space.
  • Investigate the implications of non-unique solutions in vector equations.
USEFUL FOR

Students studying linear algebra, particularly those focusing on vector calculus and cross product applications, as well as educators looking for examples of vector equation solutions.

themadhatter1
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Homework Statement


Given a = <1,2,3> and b = <1,-1,-1>, sketch the collection of all position vectors c satisfying a x b = a x c

Homework Equations





The Attempt at a Solution



I've calculated a x b = <1,4,-3> and Defining c = <x,y,z> I found a x c = <2z-3y, z-3x, y-2x>. I want to come up with an algebraic representation of the vectors so I created the following system of equations

1 = 2z - 3y
4 = 3x - z
-3 = y - 2x

So x,y, and z that satisfy all three equations are a possible vector. I'm having trouble solving it, and I'm thinking I'm just going to get a single solution to this system If I do manage to solve it and it has a solution.

Can you help?
 
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themadhatter1 said:

Homework Statement


Given a = <1,2,3> and b = <1,-1,-1>, sketch the collection of all position vectors c satisfying a x b = a x c

Homework Equations


The Attempt at a Solution



I've calculated a x b = <1,4,-3> and Defining c = <x,y,z> I found a x c = <2z-3y, z-3x, y-2x>. I want to come up with an algebraic representation of the vectors so I created the following system of equations

1 = 2z - 3y
4 = 3x - z
-3 = y - 2x

So x,y, and z that satisfy all three equations are a possible vector. I'm having trouble solving it, and I'm thinking I'm just going to get a single solution to this system If I do manage to solve it and it has a solution.

Can you help?

You are doing fine so far, I think. But if you think you will get a single solution you are jumping to conclusions. Work out the solution to your system. a x c=a x (c+k*a) for any constant k. c can't possibly be unique.
 

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