Video:How to Subtract Matriceswith Bassem Saad
Matrices are easy to subtract as long as you align the rows and columns. Watch this About.com video to learn how to subtract matrices and how this math rule is practically applied.See Transcript
Transcript:How to Subtract Matrices
Hi, my name is Bassem Saad. I'm a Math Ph.D. candidate at U.C. Davis, and I'm here today for About.com to show you how to subtract matrices.
Subtract a Three-by-Two Matrix
Remember, a matrix is a rectangular array with m rows and n columns; and for us, our rows and columns will be made up of numerical entries. For example, this is a three-by-two matrix; that is, it has three rows, two columns, and the entries are all integers. So when you subtract one matrix from another, you only want to subtract their corresponding entries. And, remember, your matrices have to be the same size in order to subtract one from another.
So let's subtract these matrices: one, minus four, is just minus three; minus four, minus one, is minus five; two, minus two, is zero; three, minus one, is two; and zero, minus one, is minus one; and finally, one, minus zero, is of course, one.
Subtract a Two-by-Two Matrix
Let's subtract another pair of matrices. These two two-by-two matrices are clearly the same dimension, which is exactly the criteria we need in order to subtract matrices. And again, when we subtract, we are subtracting their corresponding entries. So let's begin: two, minus a negative one, is three; one, minus zero, is of course, one; five, minus zero, is of course, five; and three, minus one, is just two.
Matrix subtraction is used on an ongoing basis by medical researchers, astrophysicists, engineers, and financial analysts, and now you can master the skill yourself. Thanks for watching, and to learn more, visit us on the web at About.com.