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Chapter 4
Matrices
Question | Answer |
---|---|
Demensions of a matrice; row first, column second | a matrix with m rows and n columns has dimensions m*n |
When are matrices equal? | If and only if they have the same demensions and their corresponding elements are equal. |
POINT MATRIX; with x and y | [x] 2*1 matrix [y] |
If P=(-4,1) E=(.1,6) N=(4,7) T=(6,2) A=(3,-2) write pentagon PENTA as a matrix | ...P E N T A............................... x -4 -1 4 6 3 ............................. y 1 6 7 2 -2 |
If two matrices A and B have the same demensions, their sum A+B is the matrix in which each element is the sum of the corresponding elements in A and B. | Addition is communative A+B=B+A Addition is associative (A+B)+C=A+(B+C) |
SCALAR MULTPLICATION | THe product of a scalar k and a matrix A is the matrix kA in which each elemnt is k times the corresponding elemnt in A. |
MATRIX MULTIPLICATION | The product of to matrices A and B exists only when the number of columns of A equals the number of rows of B. If A is m*n, B must be n*p in order for AB to exist. |