The so-called Sarrus rule will sound like Chinese to you or you will never have heard it, if you are not a little involved with mathematics (to a greater or lesser extent).
In fact, who uses it, if they know that this name is due to Pierre Fréderic Sarrus, who was a mathematician of French origin who, among other things, published an article related to the subject centuries ago in 1833. The new method for solving equations.
Thanks to this rule (which is called in this way, but it is still a method or a way of doing it), it is much easier to be able to solve the equations and memorize it with a little more ease. The method used for this is what they call the determinant of three by three. Therefore, Sarrus’s rule is nothing more than a mathematical method to be able to solve algebraic calculations.
It is not easy to start solving it, therefore, as advice we will tell you to read all the explanations that we will try to give you well, but, above all, practice and watch videos on the internet or booklets, to do the calculations yourself and understand it a lot better.
Instructions
- Being able to explain it in writing is not entirely easy and when mathematics has not been your forte, even less. And it is that, there are many of us, who have to do mathematical exercises was the worst thing that could happen to us. A bit contradictory, since, in life, day to day, consists of precisely calculations. Calculations for everything… buy, sell, deal, etc.
- The determining rule of three by three, or rule of three, helps to solve problems such as when more than three values are found from four or when there is an unknown, the method must be applied.
- How will we check that they are the ideal equations to solve it? There are little “tricks” for beginners… for example, we should look at the signs that accompany them.
- In general, these must have, on the one hand, signs that are positive. That is, it is the sign of the addition (+) and in the other section, they will carry the negative signs, the sign of the subtraction (-).
- To see it more clearly (if this is possible…) we are going to try to explain it in as much detail as possible and clearly and concisely. If we look at an example that we may have nearby (or search in the search engine), we will have already noticed that one section has the already mentioned positive signs and the other section has the negative signs.
- Then you have to look at the numbers in a different way than you may be used to. In this case the method is always diagonal. The main numbers, always diagonally. Those that remain in parallel are calculated by multiplying it by the number that always remains at the other end of the numbers.
- Said in this way, it may seem a bit complicated, but if you try to put it into practice, you will see everything more clearly. Always these things and the mathematical exercises can seem much more complicated to understand than they really are in practice.
- All this, summed up to the extreme, I think we could explain it as: that the numbers must always be placed, in the row below. The first two will keep their previous order already established and the others, what is done, is always adding the first three numbers, but always diagonally (not from top to bottom or straight) and the others are kept to subtract three
- We can conclude, then, that in order to arrive at Sarrus’s rule, the pertinent calculations must also have been made beforehand in order to arrive at determinant three. Well, for this, you have to go through a few steps and you have to know how to decipher the determinants that are two, and the same until you reach the determinant three. And now, it is when it is necessary to know how to decipher the determinant three and it is done with this rule, called de sarrus.
- Why is he told all the time that “determinant” number three? Because if you pay attention, the numbers that will appear will always be in rows of the numbers that are… figures or numbers that appear. But as for the negative numbers and the positive numbers (or vice versa) they will only be three figures in negative and three figures in positive.
- Studying and learning this mathematical method is always done in high school. It is difficult for people who have a harder time understanding calculations and mathematics. When you are more of letters, the mates are a bit the bone. These calculations and the Sarrus rule are within what would be algebra calculations.
- Now we explain another alternative that you can find, because there is also this Sarrus rule for the determinants of four by four and the same, to get the determinant two and three. Let’s see it.
- In order to find the matrices you have to make a method called inverted. With this method, if the matrix is regular or if the so-called determinant is any number other than zero.
- How much is it worth or what is the value of the number? The value of the determinant will be equal to zero if it is singular. But it must be taken into account that to calculate the determinants and make the formula, it must be done in square matrices.
- There are also more options… to be able to calculate the matrices, whatever their order, without a specific order, you can also use Laplace’s rule. To summarize it briefly, we will tell you that Laplace’s rule makes it possible to make the simplest matrices, to solve them.
- Making the reductions it is possible to arrive at the determinant of degree. It’s a bit hard to explain to be able to understand it without graphic examples so we’ll skip getting more involved.
- To find the determinants that we told you before, reaching the determinant of two and the determinant of three, these formulas are made and applied.
- The typical formulas and equations that are usually known or are made and solved more commonly, such as in school, institute, etc. They are the equations of “all life” vertically. But in the end, doing the Sarrus rule is nothing more than solving the equations, but diagonally and/or straight.
- Surely you will be wondering what this sarrus rule is usually used for and what it is trying to solve. TRUE? Usually for any math or algebra exercise. But in certain jobs and careers, such as mechanics or industrial (among others) it is quite common to find these formulas.
- Algebra is a formula used in mathematics. It is a branch that serves to decipher numbers and letters. In fact, algebra is immediately recognized because it has the particularity that, in its formulas, there are always letters.
- As a curiosity, did you know who invented algebra? It was the Arabs. And they did not invent it precisely for nothing mathematical, but the name is taken from a word from medicine. The words are collected and it translates in a similar way to something like putting the pieces back together. For them it was very important to draw conclusions and discover the things to calculate. For this reason, algebra was devised with that particularity. More letters than numbers. This variant (algebra) is the successor of another similar one, arithmetic. We hope that, from now on, you already know the formulas the first time, or you recognize them just by seeing the letters and/or numbers.
- There are many more successors in mathematics: they are among others (all of them complex), theorems, algorithms, arithmetic, equations, etc.
What do you need:
- Pencil, pen or marker.
- Eraser and/or tipex.
- Sheets of paper, notebook, notebook, blackboard, etc.
- In some cases, there are computer programs that help you solve them.
- Calculator.
Tips
Sarrus’ rule, in short, are calculations and formulas that are applied in algebra. In other words, pure mathematics. Numbers and calculations that, from the outset, not everyone understands or knows how to calculate.