Skip to main content
Calculate Determinant
Tick mark Image
Evaluate
Tick mark Image

Share

det(\left(\begin{matrix}0&1&3\\3&4&-2\\-1&5&8\end{matrix}\right))
Find the determinant of the matrix using the method of diagonals.
\left(\begin{matrix}0&1&3&0&1\\3&4&-2&3&4\\-1&5&8&-1&5\end{matrix}\right)
Extend the original matrix by repeating the first two columns as the fourth and fifth columns.
-2\left(-1\right)+3\times 3\times 5=47
Starting at the upper left entry, multiply down along the diagonals, and add the resulting products.
-4\times 3+8\times 3=12
Starting at the lower left entry, multiply up along the diagonals, and add the resulting products.
47-12
Subtract the sum of the upward diagonal products from the sum of the downward diagonal products.
35
Subtract 12 from 47.
det(\left(\begin{matrix}0&1&3\\3&4&-2\\-1&5&8\end{matrix}\right))
Find the determinant of the matrix using the method of expansion by minors (also known as expansion by cofactors).
-det(\left(\begin{matrix}3&-2\\-1&8\end{matrix}\right))+3det(\left(\begin{matrix}3&4\\-1&5\end{matrix}\right))
To expand by minors, multiply each element of the first row by its minor, which is the determinant of the 2\times 2 matrix created by deleting the row and column containing that element, then multiply by the element's position sign.
-\left(3\times 8-\left(-\left(-2\right)\right)\right)+3\left(3\times 5-\left(-4\right)\right)
For the 2\times 2 matrix \left(\begin{matrix}a&b\\c&d\end{matrix}\right), the determinant is ad-bc.
-22+3\times 19
Simplify.
35
Add the terms to obtain the final result.