Standard Basis

Two linearly independent vectors,
and
form a basis, because any vector in the plane can be set as a linear combination of them.
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The components of the vector that form the basis are:
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Examples
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The two vectors that form a basis cannot be parallel to one another.
Example
Which pairs of the following vectors form a basis?
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Orthogonal Basis

The two basis vectors are mutually perpendicular.
Orthonormal Basis
Standard Basis
The base formed by
and
is called the standard basis or canonical basis.
The standard basis is the base that is commonly used, so if nothing is noticed, it should be working on that basis.
Examples
Given the vectors
= (2, 1),
= (1, 4) and
= (5, 6).
1. Determine if
and
form a basis.
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2. Express
as a linear combination.
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3. Calculate the coordinates of
with respect to the base.
The coordinates of
with respect to the base are: (2, 1).
A vector
has coordinates (3, 5) in the standard basis. Which coordinates of
will be referred to the basis of
= (1, 2),
= (2, 1)?
(3, 5) = a (1, 2) + b (2, 1)
3 = a + 2b a = 3 − 2b a = 7/3
5 = 2a + b 5 = 2 (3 − 2b) + b b = 1/3
The coordinates of
in the basis B are (7/3, 1/3).
