Questions tagged [change-of-basis]
This tag is for question about changing basis of a finite dimensional vector space. For example, how does the representation of a vector, or a matrix change with the change of basis. Please don't use this tag on its own, it is better to add a more general tag which is relevant to your question, e.g. [linear-algebra] or [matrices] for better visibility.
1,219 questions
-2 votes
0 answers
43 views
Finding change of basis matrices in $\mathbb{R}^2$ [closed]
In $\mathbb{R}^2$, consider the following ordered basis: $$B=((1,0),(0,1)),\text{ }C=((-1,1),(1,1)),\text{ and }D=((\sqrt{3},1),(\sqrt{3},-1))$$ Find the change of basis matrix from $B$ to $C$, from $...
2 votes
3 answers
191 views
How do i show that the outermorphism of a linear transformation is basis independent [closed]
For a linear transformation A and a k-blade $b=v_1\wedge v_2 \wedge\dots\wedge v_k$ we take the outermorphism of $A$ acting on $b$ to mean $\underline A(b):= A(v_1)\wedge A(v_2)\wedge\dots\wedge A(v_k)...
4 votes
2 answers
172 views
Compute $\int\left(5\cos^3(t)-6\cos^4(t)+5\cos^5(t)-12\cos^6(t)\right)\,\mathrm{d}t$ using some results in Linear Algebra
This problem appears in the book: Linear Algebra and its applications - David C. Lay - Fourth Edition It appears in: Chapter 4 (Vector Spaces), Section 4.7 (Change of Basis), Exercise 18 $(4.7), \...
1 vote
0 answers
44 views
Change of coordinates in the cotangent space
I am studying differentiable manifolds and I came across the definition of cotangent space. I have a doubt on how we change coordinates in the cotangent space. Let $(A,\varphi)$ and $(B,\psi)$ be ...
0 votes
1 answer
83 views
Why the second part of the statement is given in Gram-Schmidt orthonormalisation thm
The statement of Gram-Schmidt orthonormalisation thm is: Let $\{v_1, v_2, \dots, v_n\}$ be a linearly independent set of vectors in an inner product space $V$. Then there exists an orthogonal set of ...
2 votes
1 answer
211 views
How Fourier transform Viewed as Change of basis?
This question mainly based on Jnez71 answer How is the Laplace Transform a Change of basis? We are interested in a specific basis known as the "Fourier" basis. The Fourier basis can be ...
0 votes
0 answers
75 views
Does any nice finite-dimensional subspace of $L^2$ have an orthonormal basis of nonnegative functions?
Context: the question came up while discussing function approximations in the context of computer graphics. In particular, (truncated) spherical harmonics (SH) are a popular way to encode a spherical ...
2 votes
1 answer
85 views
Difference between change of basis matrix and change of coordinates matrix.
I'm having trouble with some conflict between my book of linear algebra and my professor notes on it. The book (Poole's Linear Algebra) stated the following: Let $\beta = \{\boldsymbol{u}_1, . . . , \...
0 votes
0 answers
44 views
Obtain a basis for $\mathbb{R}^n$ by interchanging the image of one basis vector with $\vec{e}_1$
If $T:\mathbb{R}^n\to\mathbb{R}^n$ is an invertible linear transformation and $\vec{e}_1,\dots,\vec{e}_n$ are the usual base vectors for $\mathbb{R}^n$ then $T(\vec{e}_1),\dots,T(\vec{e}_n)$ is a ...
0 votes
1 answer
38 views
Orthogonal complement and relations between matrices formed from its basis
Suppose a real matrix $\mathbf{A}^{m\times n}$ with $m>n$, and $\text{rank}(\mathbf{A})=r<n$. Suppose now a real matrix $\mathbf{E}^{s\times n}$ of full rank, $s=n-r$, and in a such way that $$ \...
3 votes
1 answer
126 views
Transpose in change of basis
I've just started working my way through Shahshahani’s An Introductory Course on Differentiable Manifolds, and there's something right at the beginning that I don't quite follow. When checking how ...
0 votes
0 answers
44 views
Can we prove the independence of the family $\left(P\left(X+a_i\right)\right)$ without using matrices?
Let $\mathbb{K}$ be a field, and let $P \in \mathbb{K}_n[X]$ be a polynomial of degree $n$. Let $a_0, \ldots, a_n \in \mathbb{K}$ be $n+1$ pairwise distinct scalars. Define the family $\mathcal{F}=\...
1 vote
0 answers
87 views
Relationship Between Metric Determinant and Change-of-Basis Matrix
Let $ V $ be a vector space with an inner product $ g $ and let $\{v_i\} $ be a basis of $ V $. Consider another basis $ \{u_i\} $ that is $ g$-orthonormal, and let $ B $ be the change-of-basis ...
1 vote
1 answer
85 views
Trouble in problem about matrix of linear transformation after change of basis?
I'm having trouble with the following problem: I get that we have: $$f\left(e_1\right)=-e_2-e_3 \sin (v) \qquad f\left(e_2\right)=e_1+e_3 \cos(v)\qquad f\left(e_3\right)=-e_1 \sin (v)+e_2 \cos (v)$...
1 vote
0 answers
52 views
Is the "change of basis matrix" the same as "matrice to passage"? [duplicate]
The first course I read of Linear Algebra was French, here you can find it. In the "Matrices et applications linéaires">"Changement de bases" section the matrix that serves as ...