Vector subtraction is one of the basic operations in vector mathematics. Unlike vector addition that combines two vectors, vector subtraction produces the difference between two vectors. When we subtract vector b from vector a, the result is a vector that, when added to , will produce .
b
a
Mathematically, vector subtraction is defined as:
a−b=a+(−b)
This means that subtracting vector b from vector a is equivalent to adding vector a with the negative of vector b.
Geometrically, vector subtraction a−b can be depicted by:
Drawing vectors a and b with the same initial point.
Drawing vector −b (vector b with reversed direction).
Drawing a vector from the endpoint of b to the endpoint of a.
The resulting vector, a−b, can also be obtained by drawing a line from the endpoint of vector b to the endpoint of vector a when both vectors are drawn from the same origin point.
Visualization of Vector Subtraction in 3D Space
Vector subtraction a−b is equivalent to vector a added to the negative of vector b.
Vector subtraction can also be used to find the resultant vector. A resultant vector is a vector that represents the combined effect of two or more vectors.
Suppose an object moves from initial position p1 to final position p2. The displacement vector of the object is:
d=p2−p1
This resultant vector shows the direction and distance of the object's displacement.
A monkey is at position (3,4) and wants to get a banana located at position (2,1). Determine the displacement vector of the monkey to reach the banana.