What does a subscript mean in matrix?

What does a subscript mean in matrix?

A matrix is a rectangular array of numbers. Boldface capital letters represent matrices, and lower case letters with subscripts represent individual numbers in the matrices.

How do you read a matrix notation?

One way to remember that this notation puts rows first and columns second is to think of it like reading a book. You always read sideways first, just as you always write the rows first. To continue the analogy, when you are done reading a row in a book, your eyes move downward, just as the columns after the rows.

What does X X mean matrix?

For a rectangular m × N matrix X, X X is the N × N square matrix where a typical element is the sum of the cross products of the elements of row i and column j; the diagonal is the sum of the squares of row i.

What is i and j in a matrix?

In a matrix A, the entries will typically be named “ai,j”, where “i” is the row of A and “j” is the column of A.

What is rectangular matrix?

A rectangular matrix is a matrix in which the number of rows is NOT equal to the number of columns. It is one of the types of matrices. In geometry, a rectangle is a quadrilateral in which the length is different from its width.

What is I and J in matrix?

In a matrix A, the entries will typically be named “ai,j”, where “i” is the row of A and “j” is the column of A. For instance, given the following matrix A: …the value 4 is in the second row and the first column, so 4 is the 2,1-entry. That is, 4 = a2,1 (pronounced as “ay-sub-two-one”).

What is D in derivatives?

The d/dt represents a differentiation operator that differentiates something with respect to (in this case) time. The physical meaning of ds/dt is that if you were to draw a graph of s against t, ds/dt represents the exact slope of the graph (not the Δy/Δx which is an approximation) at a specified time.