An unknown is something that is unknown.
The notion of incognita , derived from the Latin word incognĭtus , refers to that which is unknown . The term has different uses depending on the context .
For example: "The current level of the basketball player is a mystery since he has not played for seven months" , "The mystery is over: the president announced that he will run again as a candidate and will seek re-election" , "The singer did not clear up the mystery and it remains unconfirmed whether or not he will return to his old band .
Unknown in mathematics
In the field of mathematics , an unknown quantity is called an unknown quantity that must be specified in a problem or in an equation to achieve its resolution. It can be said, therefore, that an unknown is one of the elements that constitute a mathematical expression.
In an equation , the unknown is an unknown value that, when discovered, allows equality to be verified. In a problem, there may be several unknowns, each expressed by a symbol that cannot be repeated.
The problems that are solved with the rule of three , to cite one case, are based on the presence of an unknown and three known values . Between these elements there is a linear relationship given by a proportionality.
There are different resources that allow us to reveal an unknown.
Resolution Examples
If we know that a fast food restaurant sells a hamburger for 50 pesos , and we intend to buy three hamburgers , we can use the rule of three to know the total price that we will have to pay, discovering the value of the unknown :
If a hamburger costs 50 pesos, three hamburgers cost x pesos.
1 hamburger = 50 pesos
3 hamburgers = x pesos
(3×50) / 1 = x
150 = x
This means that the unknown has a value of 150 : three hamburgers cost 150 pesos .
Other ways to solve an unknown
This is also known as the simple rule of three , to distinguish it from the compound rule , in which there is a greater number of magnitudes that are used to find out the value of the unknown. Furthermore, in the example of hamburgers we are faced with a case of a simple direct rule of three, since all magnitudes increase or decrease in the same direction, with direct proportionality .
We can explain this by thinking about each one of them: we have the price of a hamburger, which is fifty pesos, and we want to find out the price of three hamburgers. Well, if we increase any of these three values, we will be forced to increase the other two in the same proportion : if we knew the price of four hamburgers, that is, if we multiplied the previous data by four, then the two remaining magnitudes would be two hundred pesos. and twelve hamburgers.
The concept in everyday life
The concept of unknown has been part of mathematics for centuries, always with the aim of modeling algebraic problems of polynomials, that is, expressions formed by a finite number of variables and products between constants and variables. No matter how foreign mathematical theory may seem to us in everyday life, it could not be more present: every day we make decisions related to quantities, amounts of money, the order of things in a system, etc., and for all that and much more we use this science automatically.
This brings us to the apparently negative nuance that the term unknown receives in everyday speech: although it can also serve to denote mystery in an attractive sense, it is generally used when this lack of knowledge causes us an inconvenience. In mathematics, it is thanks to this doubt that problems exist, and they are what move knowledge forward, the very reasons for research and constant learning. If there were no things to resolve, then everything would lose meaning , since life would become static.