Precalculus Examples
[0301430312241234]
Step 1
Step 1.1
Consider the corresponding sign chart.
|+-+--+-++-+--+-+|
Step 1.2
The cofactor is the minor with the sign changed if the indices match a - position on the sign chart.
Step 1.3
The minor for a11 is the determinant with row 1 and column 1 deleted.
|303224234|
Step 1.4
Multiply element a11 by its cofactor.
0|303224234|
Step 1.5
The minor for a12 is the determinant with row 1 and column 2 deleted.
|403124134|
Step 1.6
Multiply element a12 by its cofactor.
-3|403124134|
Step 1.7
The minor for a13 is the determinant with row 1 and column 3 deleted.
|433124124|
Step 1.8
Multiply element a13 by its cofactor.
0|433124124|
Step 1.9
The minor for a14 is the determinant with row 1 and column 4 deleted.
|430122123|
Step 1.10
Multiply element a14 by its cofactor.
-1|430122123|
Step 1.11
Add the terms together.
0|303224234|-3|403124134|+0|433124124|-1|430122123|
0|303224234|-3|403124134|+0|433124124|-1|430122123|
Step 2
Multiply 0 by |303224234|.
0-3|403124134|+0|433124124|-1|430122123|
Step 3
Multiply 0 by |433124124|.
0-3|403124134|+0-1|430122123|
Step 4
Step 4.1
Choose the row or column with the most 0 elements. If there are no 0 elements choose any row or column. Multiply every element in row 1 by its cofactor and add.
Step 4.1.1
Consider the corresponding sign chart.
|+-+-+-+-+|
Step 4.1.2
The cofactor is the minor with the sign changed if the indices match a - position on the sign chart.
Step 4.1.3
The minor for a11 is the determinant with row 1 and column 1 deleted.
|2434|
Step 4.1.4
Multiply element a11 by its cofactor.
4|2434|
Step 4.1.5
The minor for a12 is the determinant with row 1 and column 2 deleted.
|1414|
Step 4.1.6
Multiply element a12 by its cofactor.
0|1414|
Step 4.1.7
The minor for a13 is the determinant with row 1 and column 3 deleted.
|1213|
Step 4.1.8
Multiply element a13 by its cofactor.
3|1213|
Step 4.1.9
Add the terms together.
0-3(4|2434|+0|1414|+3|1213|)+0-1|430122123|
0-3(4|2434|+0|1414|+3|1213|)+0-1|430122123|
Step 4.2
Multiply 0 by |1414|.
0-3(4|2434|+0+3|1213|)+0-1|430122123|
Step 4.3
Evaluate |2434|.
Step 4.3.1
The determinant of a 2×2 matrix can be found using the formula |abcd|=ad-cb.
0-3(4(2⋅4-3⋅4)+0+3|1213|)+0-1|430122123|
Step 4.3.2
Simplify the determinant.
Step 4.3.2.1
Simplify each term.
Step 4.3.2.1.1
Multiply 2 by 4.
0-3(4(8-3⋅4)+0+3|1213|)+0-1|430122123|
Step 4.3.2.1.2
Multiply -3 by 4.
0-3(4(8-12)+0+3|1213|)+0-1|430122123|
0-3(4(8-12)+0+3|1213|)+0-1|430122123|
Step 4.3.2.2
Subtract 12 from 8.
0-3(4⋅-4+0+3|1213|)+0-1|430122123|
0-3(4⋅-4+0+3|1213|)+0-1|430122123|
0-3(4⋅-4+0+3|1213|)+0-1|430122123|
Step 4.4
Evaluate |1213|.
Step 4.4.1
The determinant of a 2×2 matrix can be found using the formula |abcd|=ad-cb.
0-3(4⋅-4+0+3(1⋅3-1⋅2))+0-1|430122123|
Step 4.4.2
Simplify the determinant.
Step 4.4.2.1
Simplify each term.
Step 4.4.2.1.1
Multiply 3 by 1.
0-3(4⋅-4+0+3(3-1⋅2))+0-1|430122123|
Step 4.4.2.1.2
Multiply -1 by 2.
0-3(4⋅-4+0+3(3-2))+0-1|430122123|
0-3(4⋅-4+0+3(3-2))+0-1|430122123|
Step 4.4.2.2
Subtract 2 from 3.
0-3(4⋅-4+0+3⋅1)+0-1|430122123|
0-3(4⋅-4+0+3⋅1)+0-1|430122123|
0-3(4⋅-4+0+3⋅1)+0-1|430122123|
Step 4.5
Simplify the determinant.
Step 4.5.1
Simplify each term.
Step 4.5.1.1
Multiply 4 by -4.
0-3(-16+0+3⋅1)+0-1|430122123|
Step 4.5.1.2
Multiply 3 by 1.
0-3(-16+0+3)+0-1|430122123|
0-3(-16+0+3)+0-1|430122123|
Step 4.5.2
Add -16 and 0.
0-3(-16+3)+0-1|430122123|
Step 4.5.3
Add -16 and 3.
0-3⋅-13+0-1|430122123|
0-3⋅-13+0-1|430122123|
0-3⋅-13+0-1|430122123|
Step 5
Step 5.1
Choose the row or column with the most 0 elements. If there are no 0 elements choose any row or column. Multiply every element in row 1 by its cofactor and add.
Step 5.1.1
Consider the corresponding sign chart.
|+-+-+-+-+|
Step 5.1.2
The cofactor is the minor with the sign changed if the indices match a - position on the sign chart.
Step 5.1.3
The minor for a11 is the determinant with row 1 and column 1 deleted.
|2223|
Step 5.1.4
Multiply element a11 by its cofactor.
4|2223|
Step 5.1.5
The minor for a12 is the determinant with row 1 and column 2 deleted.
|1213|
Step 5.1.6
Multiply element a12 by its cofactor.
-3|1213|
Step 5.1.7
The minor for a13 is the determinant with row 1 and column 3 deleted.
|1212|
Step 5.1.8
Multiply element a13 by its cofactor.
0|1212|
Step 5.1.9
Add the terms together.
0-3⋅-13+0-1(4|2223|-3|1213|+0|1212|)
0-3⋅-13+0-1(4|2223|-3|1213|+0|1212|)
Step 5.2
Multiply 0 by |1212|.
0-3⋅-13+0-1(4|2223|-3|1213|+0)
Step 5.3
Evaluate |2223|.
Step 5.3.1
The determinant of a 2×2 matrix can be found using the formula |abcd|=ad-cb.
0-3⋅-13+0-1(4(2⋅3-2⋅2)-3|1213|+0)
Step 5.3.2
Simplify the determinant.
Step 5.3.2.1
Simplify each term.
Step 5.3.2.1.1
Multiply 2 by 3.
0-3⋅-13+0-1(4(6-2⋅2)-3|1213|+0)
Step 5.3.2.1.2
Multiply -2 by 2.
0-3⋅-13+0-1(4(6-4)-3|1213|+0)
0-3⋅-13+0-1(4(6-4)-3|1213|+0)
Step 5.3.2.2
Subtract 4 from 6.
0-3⋅-13+0-1(4⋅2-3|1213|+0)
0-3⋅-13+0-1(4⋅2-3|1213|+0)
0-3⋅-13+0-1(4⋅2-3|1213|+0)
Step 5.4
Evaluate |1213|.
Step 5.4.1
The determinant of a 2×2 matrix can be found using the formula |abcd|=ad-cb.
0-3⋅-13+0-1(4⋅2-3(1⋅3-1⋅2)+0)
Step 5.4.2
Simplify the determinant.
Step 5.4.2.1
Simplify each term.
Step 5.4.2.1.1
Multiply 3 by 1.
0-3⋅-13+0-1(4⋅2-3(3-1⋅2)+0)
Step 5.4.2.1.2
Multiply -1 by 2.
0-3⋅-13+0-1(4⋅2-3(3-2)+0)
0-3⋅-13+0-1(4⋅2-3(3-2)+0)
Step 5.4.2.2
Subtract 2 from 3.
0-3⋅-13+0-1(4⋅2-3⋅1+0)
0-3⋅-13+0-1(4⋅2-3⋅1+0)
0-3⋅-13+0-1(4⋅2-3⋅1+0)
Step 5.5
Simplify the determinant.
Step 5.5.1
Simplify each term.
Step 5.5.1.1
Multiply 4 by 2.
0-3⋅-13+0-1(8-3⋅1+0)
Step 5.5.1.2
Multiply -3 by 1.
0-3⋅-13+0-1(8-3+0)
0-3⋅-13+0-1(8-3+0)
Step 5.5.2
Subtract 3 from 8.
0-3⋅-13+0-1(5+0)
Step 5.5.3
Add 5 and 0.
0-3⋅-13+0-1⋅5
0-3⋅-13+0-1⋅5
0-3⋅-13+0-1⋅5
Step 6
Step 6.1
Simplify each term.
Step 6.1.1
Multiply -3 by -13.
0+39+0-1⋅5
Step 6.1.2
Multiply -1 by 5.
0+39+0-5
0+39+0-5
Step 6.2
Add 0 and 39.
39+0-5
Step 6.3
Add 39 and 0.
39-5
Step 6.4
Subtract 5 from 39.
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