ANSWER =
det A 4X4 =
det B 4X4 =
det C 4X4 =
det D 4X4=
det E 4X4=
Determinant of 5 x 5 = det A 4X4 - det B 4X4 + det C 4X4 - det D 4X4 + det E 4x4
PRACTICE EXERCISE IN USING THE ABOVE CALCULATOR
| 5 | 1 | 1 | 1 | 1 | |
| 2 | 5 | 2 | 2 | 2 | |
| 7 | 7 | 45 | 3 | 5 | |
| 4 | 9 | 3 | 1 | 1 | |
| 59 | 7 | 2 | 1 | 1 | |
| Answer is -718 |
Reviewer on how to compute for determinant value of 4 x 4 Matrix using expansion by co-factor method
In example shown below, Matrix A is size 4 x 4 because it has 4 rows and 4 columns. Mapping all the inputs to variables small letter "a" through "p". Then you can see how the co-factor works to compute the determinant of 4 x 4 matrix A. The first variable small letter "a" = 3 will be multiplied by the determinant co-factor of 3 x 3 matrix. Repeat the process for variable letter "e" with negative sign preceding the answer.Next repeat the process for variable letter "i" this time use the positive sign preceding the answer. Continue repeating the process and alternating the positive and negative sign preceeding the answer. Next you do the basic math of multiplication, addition and subtraction and you will solve the determinant of matrix A is 20. Doing this calculation by hand is very time consuming but thanks to computer and internet advancement, it is now possible to solve this problem in a minute using your smartphone or laptop. Now our brain can be used for higher level of thinking such as scenario analyis and decision making.
Acquiring knowledge and skill on how to solve for determinant of 4 x 4 matrix is important in solving any four simultaneous linear equation. Click this link to see example of using determinant of 4 x 4 matrix to solve four simultaneous linear equations.