1. 4.1 MATRIX OPERATIONS

2. WHAT IS A MATRIX?
A group of numbers arranged in rows
and columns.
 Its numbers are called entries or
elements.
 The dimensions are:
# of rows x # of columns
 Example:
 This matrix has dimension 2 x 3

3. SPECIAL MATRICES
Name Description Example
Row Matrix only 1 row
Column Matrix only 1 column
same # of rows
Square matrix
and columns
all entries are
Zero Matrix
zeros

4. COMPARING MATRICES
 Two matrices are equal if their dimensions
are the same and corresponding entries are
equal.
 Are these equal?

5. ADDING AND SUBTRACTING MATRICES
 Dimensions must match!
 Add or subtract corresponding entries.
 Examples:
Not Possible!

6. YOUR TURN!
 Perform the indicated operation, if possible.
a.
b.
c.

7. MULTIPLYING BY A SCALAR
 Scalar – a regular number
 Scalar multiplication – multiplying a
matrix by a scalar
 Just multiply each entry by the scalar!
Example:

8. EXAMPLE:
 Perform the indicated operation(s), if
possible.

9. YOUR TURN!
 Perform the indicated operation(s).

10. SOLVING MATRIX EQUATIONS
 Simplify,then write equations for
corresponding entries and solve.
 Example:
Solve for x and y.

11. YOUR TURN!
 Solve the matrix equation for x and y: