Left Parenthesis Symbol
The left parenthesis symbol is used in combination with the right parenthesis symbol to group one or more expressions together. Parentheses are also used to represent multiplication and within the notation of a function. Typically parentheses are used in an expression like this:
In the expression above, the parentheses groups the expression together so that the addition occurs before the multiplication. In plain language, this means add the numbers one and two together, then multiply the result by three. This changes the order of operations and produces a different result than if the parentheses were not there.
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Usage
A function takes input and produces output. The idea is a useful way to abstract away complexity and, especially in the age of computers, is a practical tool to solve problems.
In mathematics parentheses are used to group expressions to be evaluated together and organize the order of operations. Everything within the parantheses is evaluated, then the rest of the calculation is carried out.
Two expressions placed next to eachother and separated by parenthesis are assumed to be multiplied together.
The order of operations is an agreed upon standard that describes what operations should be performed first in a math expression.