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Vectors as Data

Vector Subtraction

Vector subtraction compares vectors by subtracting matching components.

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Vector Subtraction

Definition

Vector subtraction subtracts matching components.

Example:

[7, 9] - [2, 4] = [5, 5]

Because:

7 - 2 = 5
9 - 4 = 5

Vector subtraction = component-by-component difference.


Same Dimension Requirement

Like addition, subtraction requires the same dimension.

Valid:

[7, 9] - [2, 4]

Invalid:

[7, 9] - [2, 4, 1]

The components do not line up.

Subtraction requires matching structure.


Subtraction As Difference

Subtraction can show how one vector differs from another.

Example:

current = [8, 10]
target  = [5, 4]

Difference:

current - target = [3, 6]

This means:

first component differs by 3
second component differs by 6

Vector subtraction exposes component-level differences.


Subtraction As Movement

If two vectors represent positions, subtraction can describe movement between them.

Example:

start = [2, 3]
end   = [7, 8]

Movement from start to end:

end - start = [5, 5]

So [5, 5] is the change needed to get from the first position to the second.

Subtraction can produce a change vector.


Order Matters

Vector subtraction is not the same in both directions.

Example:

[7, 9] - [2, 4] = [5, 5]
[2, 4] - [7, 9] = [-5, -5]

The size of the difference may match, but the direction is opposite.

Subtraction keeps track of direction of change.


Relation To Addition

Subtraction can be understood as adding the opposite vector.

Example:

[7, 9] - [2, 4]

is the same as:

[7, 9] + [-2, -4]

Result:

[5, 5]

Subtraction is addition with an additive inverse.


Final Summary

  • Vector subtraction subtracts matching components.
  • Vectors must have the same dimension.
  • Subtraction can measure difference.
  • Subtraction can describe movement from one vector to another.
  • Order matters.
  • Subtraction is connected to additive inverse.

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Continue the series.

Scalar Multiplication