MATH/행렬대수학

chapter2.1 linear transformation and matrices

mjmjpp 2023. 11. 30. 21:55

chapter 2.1 Linear Transformations of Euclidean Spaces(선형변환함수)

linear system of the form Ax = b with an m x n matrix A

->we could regard Ax as a function and view Ax = b as meaning that the function maps the vector x to the vector b.

=> f(x) = Ax with an m x n matrix A

the domain(정의역) of this function should be a subset of Rn, the codomain(공역) be a subset of Rm

 

f(av1 + bv2) = (av1 + bv2) = aAv1 + bAv2 =af(v1)+bf(v2)

->such functions of the for Ax preserve the linear combinations

=> The functions in a vector space that preserve the linear combinations=linear transformations

 

A function T : Rn -> Rm 은 두 조건들을 만족해야 a linear transformation로 볼 수 있다.

Rn에 속하는 all vectors u, v , all scalars r.

 

linear transformations(선형변환)은 linear combination(선형결합)을 보존한다.

이 특성은 선형 변환이 공역에서 정의역의 일부 대수 구조를 보존한다는 것을 보여줍니다.

 

 

1) T(u+v)=T(u)+T(v) 조건을 만족한다.
2) T(ru)=rT(u) 조건을 만족한다.

a linear transformation of R into R is completely determined by the value of T(1)

a linear transformation T : Rn -> Rm is determined by its values on a basis for Rn

 

T : Rn -> Rm be a linear transformation, and let B = {b1, . . . , bn} be a basis for Rn

v ∈ Rn에서,the vector T(v) is uniquely determined by the vectors T(b1), . . . ,T(bn)

 

the unique linear combination of b1, . . . , bn so that v = r1b1+· · ·+rnbn

T is a linear transformation->

{e1, . . . , en} be the standard basis for Rn이고 T : Rn -> Rm 는 a linear transformation라 두자

the matrix A = [T(e1), . . . ,T(en)]

A : jth column is T(ej) 을 갖는 m x n matrix ,T(x) = A(x) ( x ∈ Rn)