# Determinant of 3×3 matrix online

Calcular el determinante de una matriz 3x3 online is possible with our calculator. Just fill in the elements that make up the determinant and click on the calculate button to see the result, including the step-by-step method of solving the attached determinants.

We will also teach you how to resolver determinantes de 3x3 by the Sarrus method or using Excel. Read on and you will find all this information and much more.

## Cómo resolver determinantes 3x3 por Sarrus

The Sarrus rule es una forma muy sencilla de calcular el determinante de una matriz 3x3. Este método se compone de dos partes:

• Sign +: the elements of the diagonal of the determinant and those of the parallel diagonals are multiplied together with their opposite vertex.
• Sign -: the elements of the secondary diagonal are multiplied as well as those of the parallel diagonals taking into account their opposite vertex.

The regla de Sarrus para resolver determinantes de 3x3 is a little difficult to understand in theory, so the best thing to do is to look at the image in which we show the order in which the multiplications must be done, both for the positive part and for the part that accompanies the negative sign.

In addition, here is an example of how resolver un determinante 3x3 genérico por Sarrus:

## Obtener determinante de matriz 3x3 por adjuntos

The method of adjoint determinants is another form of resolver determinantes 3x3. In this case, you have to choose a row or column of the matrix, preferably with zeros to facilitate the calculations. If there is none that meets this criterion, you can take the one you want.

Now that you have selected a row or column, you need to multiplying each element of the selected line by its adjoining determinant (el que se obtiene al eliminar la fila y columna en la que se encuentra dicho elemento). También debes tener en cuenta el signo + o - de ese elemento teniendo en cuenta la siguiente disposición:

If you are looking for an example of how to use the attachment method, pásate por el enlace que te hemos dejado y ahí encontrarás uno. Aunque sea para una matriz 4x4, el procedimiento a seguir es exactamente el mismo.

## Calcular determinante 3x3 en Excel

With Excel you can also calcular un determinante de una matriz 3x3 as you can see in the video we have recorded.

Just open a spreadsheet and write each element of the matrix in an empty cell, respecting its order. When you have filled in all the elements of the matrix in Excel, in the next step, place yourself in an empty cell and type the following function:

=MDETERM()

Entre los paréntesis debes escribir o seleccionar el rango de celdas que ocupa tu matriz 3x3 en la hoja de Excel. En nuestro ejemplo del vídeo, escribiríamos así la función de Excel para solve the determinant of the matrix:

=MDETERM(B4:D6)

Sin duda, es una forma muy rápida de comprobar si has resuelto bien el determinante 3x3 o de ahorrar tiempo y evitar posibles errores de cálculo.