limit
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 2x + 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.
