The word for the punctuation mark, on the other hand, comes from Îºá¿¶Î»Î¿Î½ (or kÅlon), which means âlimbâ or âclauseâ â and it is used because one of the main functions of the colon is to separate two clauses, where the second clause explains or follows from the first.
The goal in solving an equation is to get the variable by itself on one side of the equation and a number on the other side of the equation. To isolate the variable, we must reverse the operations acting on the variable. We do this by performing the inverse of each operation on both sides of the equation.
Note, the above is not a definition, merely a pithy description. Just as subtraction is the inverse operation of addition, and taking a square root is the inverse operation of squaring, exponentiation and logarithms are inverse operations. Finding an antilog is the inverse operation of finding a log, so is another name for exponentiation. However, historically, this was done as a table lookup. Some history was given earlier and the formal definition is repeated below, this time with restrictions.