Can the Inverse of an Inner Product Be Described as a Function of Two Vectors?

In summary, the conversation discusses the possibility of describing a function, a=f(b,c), where a is not completely determined by b and c due to the ability to replace a with a+d in the first equation, as long as d is orthogonal to b. The problem regarding vortex dynamics is also mentioned, specifically using the law of Biot and Savart to determine the velocity field induced by a vortex filament. The use of the Dirac Delta function and substitutions for the vorticity are discussed, with the conclusion that it is not possible to write the vorticity as a function of the other variables. The conversation ends with the solution being found and a summary of the steps taken.
  • #1
steem84
13
0
my question is:

if a.b=c

with
a=any vector
b=any vector
.=inner product
c=resulting scalar

is there a way to describe a=f(b,c)?

Thanks
 
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  • #2
No. a isn't completely determined by b and c, since you can replace a with a+d in your first equation, if d is orthogonal to b.
 
  • #3
No. Think of it this way: Suppose you find vectors a and d such that a.b = c and d.b=0 (i.e., d is orthogonal to b). Then for any scalar k, (a+k*d).b=c also. In other words, the solution to a.b=c is not unique.
 
  • #4
Ok thanks!

but it did not solve my problem regarding vortex dynamics...

I would like to use the the law of Biot and Savart to determine the velocity field induced by a vortex filament. I am trying to do this by rewriting the equation of the circulation to a function for the vorticity.

To do this, I am using the Dirac Delta function for another integral for the circulation. This way i can equal the two integrands. But from that expression I would like to write the vorticity as a function of the rest (to substitute it in Biot ans Savart). But from your explanations I see that this is not possible??
 

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  • #5
already solved it...

w.n = the magnitude of the vector=length(w)
x=f(s)
dx/ds / length(dx/ds) = unity direction of the vector

so the vector is w is determined to be (w.n)*(dx/ds / length(dx/ds))
 

FAQ: Can the Inverse of an Inner Product Be Described as a Function of Two Vectors?

What is the inverse of an inner product?

The inverse of an inner product is a mathematical operation that reverses the effect of an inner product. It can be thought of as a way to "undo" the multiplication between two vectors in an inner product space.

How is the inverse of an inner product different from the inverse of a regular multiplication?

The inverse of an inner product is different from the inverse of a regular multiplication because it takes into account the specific properties and structure of an inner product space. In an inner product space, the inverse is defined using the concept of adjoint operators, whereas in regular multiplication, the inverse is simply the reciprocal of the number being multiplied.

What is the importance of the inverse of an inner product in mathematics?

The inverse of an inner product is an important concept in mathematics because it allows for the solution of many problems in linear algebra and functional analysis. It is also used in the definition and study of orthogonal projections and orthogonal complements, which have various applications in fields such as signal processing and quantum mechanics.

How is the inverse of an inner product used in machine learning and data analysis?

In machine learning and data analysis, the inverse of an inner product is used in algorithms such as principal component analysis (PCA) and linear discriminant analysis (LDA). These algorithms rely on finding the inverse of the inner product matrix to perform dimensionality reduction and feature extraction.

Are there any limitations to using the inverse of an inner product?

One limitation of using the inverse of an inner product is that it may not exist for all inner product spaces. In cases where the inverse does not exist, alternative methods such as generalized inverses can be used. Additionally, the computation of the inverse of an inner product can be computationally expensive for large matrices, so other approaches may be more efficient.

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