Core Pure - Matrices + Linear Transformations Flashcards
What is a square vector?
A matrix when the number of rows and columns are the same
What is an identity matrix?
A square matrix with 1’s along the principal diagonal and the rest of the elements as 0
How do you find the determinant of a 2x2 matrix?
How do you find the determinant of a 3x3 matrix?
What is a singular matrix?
A matrix where Det M = 0
How do you find the inverse of a 2x2 matrix?
What is the property of an inverse matrix?
MM⁻¹ = I
How do you find the inverse of a 3x3 matrix?
- Find the determinant of A, Det A
- Form the matrix of minors, M
- From the matrix of minors, form the matrix of cofactors, C
- Find the Transpose of the matrix of cofactors, Cᵀ
- A⁻¹ = (1/DetA) Cᵀ
What is the transpose of a matrix?
The reflection across the main diagonal
If the determinant of a matrix corresponding to 3 simultaneous equations is singular, is it consistent or inconsistent and how many solutions does it have?
If Det A = 0, the simulatanous equations may:
* Be consistnent and have infinite solutions
* Or be inconsistent and no solutions
If the determinant of a matrix corresponding to 3 simultaneous equations is non-singular, is it consistent or inconsistent and how many solutions does it have?
Is is consistant and has 1 unique solution
What is the gemoetrical representation of a matrix corresponding to 3 simultaneous equations when the determinant does NOT equal 0?
What is the gemoetrical representation of a matrix corresponding to 3 simultaneous equations when it is singular and has infinite solutions?
What is the gemoetrical representation of a matrix corresponding to 3 simultaneous equations when it is singular and has no solutions?
How do you determine whether 3 simultaneous equations with det A = 0 are consistent or inconsistent?
Form 2 equations from the 3 equatiosn (set 1 equal to x,y or z and substitute in to other 2), of the 2 formed equations are multiples of each other, it is consistent, if they are not multiples, they are inconsistent