In mathematics, a limit is a value toward which an expression converges as one or more variables approach certain values. Limits are important in calculus and analysis.
Consider the limit of the expression 2 x + 3 as x approaches 0. It is not difficult to see that this limit is 3, because we can assign the value 0 to the variable x and perform the calculation directly. This sort of substitution is not possible, however, when we consider the limit of the expression 1/ x - 2 as x increases without limit. (The expression for this is ' x approaches infinity.') It is apparent that 1/ x approaches 0 as 1/ x approaches infinity, although we cannot directly substitute infinity for x and calculate 1/ x = 0. The limit, as x approaches infinity, of 1/ x - 2 is therefore equal to -2.
These expressions would be denoted in mathematical literature as follows:
The term 'limit' is symbolized 'Lim.' The arrow means 'approaches.' Infinity is symbolized by the sideways 8.
Also see infinity and Mathematical Symbols .