All GRE Subject Test: Math Resources
Example Questions
Example Question #11 : Linear Algebra
Given the following matrix, find the determinant, if possible.
There is no determinant.
Write the formula to find the determinant given a 2 by 2 matrix.
Substituting in the given matrix we are able to find the determinant.
Example Question #12 : Linear Algebra
Evaluate the determinant of the following matrix.
Remember, to evaluate the determinant of a matrix use the following:
The first step would be to write the determinant of the matrix:
Now we can evaluate:
Example Question #13 : Linear Algebra
Evaluate the determinant of the following matrix.
To find the determinant of a 3 x 3 matrix, we must use the following:
The first thing we must do is write the determinant:
Now we can proceed to evaluate the determinant
Notice that the numbers 2, 4, and 3 are being multiplied by the determinants of the 2x2 matrices so we have:
Example Question #1 : Determinants
Find the determinant of the matrix:
Step 1: We need to recall how to find the determinant of a matrix. To find the determinant of a matrix, we need to use the equation , where =Determinant, and are from the matrix.
Step 2: Identify a,b,c, and d in the original matrix.
a=first number on top row, b=second number on top row (next to a), c=first number on the bottom row, and d is the second number on the bottom row (next to c).
In this matrix, a=, b=, c=, and d=.
Step 3: Substitute the values of a,b,c, and d into the equation to find the determinant of the matrix.
We will simplify the right side.
. We see that there are two negative signs in the middle, which will become a plus sign.
. Simplify the right side.
. is the determinant.
The determinant of the matrix is .
Example Question #2 : Determinants
Find the determinate of Matrix A.
Matrix A is given below.
The formula for the determinate of a 2x2 matrix is:
Plugging in the values gives us: