Linearly independent but not orthogonal, how come?

In summary, the conversation discusses the difference between linearly independent vectors and orthogonal vectors. While a set of orthogonal vectors are always linearly independent, the reverse is not always true. The group also discusses an example in R2 to illustrate this distinction.
  • #1
physlad
21
0
Hi everyone, I was reading about Gram-Schmidt process of converting two linearly independent vectors into orthogonal basis. But, as I understand, if two vectors are linearly independent then they are orthogonal! isn't that right??
Could anybody explain... please.
 
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  • #2
No. What does it mean to have a set of linearly independent vectors? What does it mean to have a set of orthogonal vectors?
 
  • #3
As I understand, a set of linearly independent vectors means that it is not possible to write any of them in terms of the others.
a set of orthogonal vectors means that the dot product of any two of them is zero. which in turn means that they are independent of each other, right? that's what confuses me.
 
  • #4
Vectors which are orthogonal to each other are linearly independent. But this does not imply that all linearly independent vectors are also orthogonal. Take i+j for example. The linear span of that i+j is k(i+j) for all real values of k. and you can visualise it as the vector stretching along the x-y plane in a northeast and southwest direction. However, there does not exist any value of k such that k(i+j) = i. i and i+j are linearly independent, but not orthogonal.
 
  • #5
For example, in R2, the vectors <1, 0> and <1, 1,> are independent since the only way to have a<1, 0>+ b<1, 1>= 0 is to have a= 0 and b= 0. But they are NOT "orthogonal"- the angle between them is 45 degrees, not 90.

As Defennndeer said, if two vectors are orthogonal, then they are linearly independent but it does NOT work the other way.
 

What does it mean for vectors to be linearly independent but not orthogonal?

Linear independence and orthogonality are two different concepts in linear algebra. Linear independence refers to a set of vectors that cannot be written as a linear combination of each other. Orthogonality, on the other hand, refers to vectors that are perpendicular to each other. Therefore, it is possible for vectors to be linearly independent but not orthogonal.

How can vectors be linearly independent but not orthogonal?

In order for vectors to be linearly independent, they must have different directions. However, for vectors to be orthogonal, they must have perpendicular directions. Therefore, it is possible for vectors to be linearly independent but not orthogonal if they have different, but not perpendicular, directions.

What is an example of vectors that are linearly independent but not orthogonal?

An example of vectors that are linearly independent but not orthogonal is the standard basis vectors in three-dimensional space: i = (1, 0, 0), j = (0, 1, 0), and k = (0, 0, 1). These vectors have different directions, but are not perpendicular to each other.

Why is it important to understand the difference between linear independence and orthogonality?

Understanding the difference between linear independence and orthogonality is important in linear algebra because these concepts have different implications and applications. Linear independence is important for solving systems of linear equations and determining the dimension of a vector space. Orthogonality, on the other hand, is important for vector projections and orthogonal transformations.

Can vectors be both linearly independent and orthogonal?

No, vectors cannot be both linearly independent and orthogonal. If two vectors are orthogonal, they must have a dot product of 0. However, for vectors to be linearly independent, their dot product must be non-zero. Therefore, if vectors are orthogonal, they cannot be linearly independent.

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