All SAT II Math II Resources
Example Questions
Example Question #4 : Matrices
Give the determinant of the matrix
The determinant of the matrix is
.
Substitute , :
Example Question #3 : Matrices
Multiply:
The product of a 2 x 2 matrix and a 2 x 1 matrix is a 2 x 1 matrix.
Multiply each row in the first matrix by the column matrix by multiplying elements in corresponding positions, then adding the products, as follows:
Example Question #1 : Matrices
Let .
Give .
is not defined.
is not defined.
has three rows and two columns; since the number of rows is not equal to the number of columns, is not a square matrix, and, therefore, it does not have an inverse.
Example Question #1 : Matrices
Define matrix .
For which of the following matrix values of is the expression defined?
I:
II:
III:
I only
I and II only
II and II only
I and III only
I, II, and III
I only
For the matrix sum to be defined, it is necessary and sufficent for and to have the same number of rows and the same number of columns. has three rows and two columns; of the three choices, only (I) has the same dimensions.
Example Question #7 : Matrices
Let and be the 2 x 2 identity matrix.
Let .
Which of the following is equal to ?
The 2 x 2 identity matrix is .
, or, equivalently,
,
so
Subtract the elements in the corresponding positions:
Example Question #81 : Mathematical Relationships
Calculate:
To add two matrices, add the elements in corresponding positions:
Example Question #81 : Mathematical Relationships
Solve for :
or
or
The equation has no solution.
or
The determinant of a matrix can be evaluated as follows:
Therefore, the equation can be rewritten:
The solution set is
or .
Example Question #11 : Matrices
Multiply:
The matrices cannot be multiplied.
The matrices cannot be multiplied.
Two matrices can be multiplied if and only if the number of columns in the first matrix and the number of rows in the second are equal. The first matrix has two columns; the second matrix has one row. This violates the condition, so they cannot be multiplied in this order.
Example Question #92 : Mathematical Relationships
Evaluate:
The determinant of the matrix is
.
Substitute :
Example Question #12 : Matrices
Define .
Give .
is not defined.
The inverse of a 2 x 2 matrix , if it exists, is the matrix
.
First, we need to establish that the inverse is defined, which it is if and only if the determinant .
Set , and check:
The inverse exists.
The process: First, switch the upper-left and lower-right entries, and change the other two entries to their opposites:
Then divide the new matrix elementwise by the determinant of the original matrix, which is .
The inverse is
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