Complete Guide to Foundational Vector Operations: Addition, Scaling, and More

Building on the fundamentals, vector addition combines two vectors by placing them tail-to-head, resulting in a new vector that represents their cumulative effect. Subtraction involves reversing the direction of one vector and then adding it to the other, effectively finding the difference between them. Scalar multiplication stretches or shrinks a vector by a numerical factor, altering its magnitude while maintaining its direction. These operations are foundational for analyzing forces, movements, and other multidimensional phenomena.

Mathematical Operations on Vectors

Vector operations are essential for manipulating and analyzing vectors in multidimensional space. The fundamental operations include addition, subtraction, and scalar multiplication.

Vector Addition

Given two vectors \( \mathbf{a} = \langle a_1, a_2 \rangle \) and \( \mathbf{b} = \langle b_1, b_2 \rangle \),

\([
\mathbf{a} + \mathbf{b} = \langle a_1 + b_1, a_2 + b_2 \rangle
]\)

This operation combines corresponding components of the vectors to produce a new vector.

Vector Subtraction

Given two vectors \( \mathbf{a} = \langle a_1, a_2 \rangle \) and \( \mathbf{b} = \langle b_1, b_2 \rangle \),

\([
\mathbf{a} – \mathbf{b} = \langle a_1 – b_1, a_2 – b_2 \rangle
]\)

Subtraction finds the difference between corresponding components, resulting in a new vector.

Scalar Multiplication

Given a scalar \( c \) and a vector \( \mathbf{a} = \langle a_1, a_2 \rangle \),

\([
c \cdot \mathbf{a} = \langle c \cdot a_1, c \cdot a_2 \rangle
]\)

This operation scales each component of the vector by the scalar \( c \), altering its magnitude while maintaining its direction.

Example

Consider vectors \( \mathbf{u} = \langle 3, 4 \rangle \) and \( \mathbf{v} = \langle 1, 2 \rangle \), and scalar \( k = 2 \).

• Addition:

\([
\mathbf{u} + \mathbf{v} = \langle 3 + 1, 4 + 2 \rangle = \langle 4, 6 \rangle
]\)

• Subtraction:

\([
\mathbf{u} – \mathbf{v} = \langle 3 – 1, 4 – 2 \rangle = \langle 2, 2 \rangle
]\)

• Scalar Multiplication:

\([
k \cdot \mathbf{u} = 2 \cdot \langle 3, 4 \rangle = \langle 6, 8 \rangle
]\)

These operations are foundational for more advanced vector analyses and applications in various scientific and engineering fields.