Operation that involves estimating the value of a function for a value of the variable taken outside the interval in which the relationship was established.
Example
From the values of log(5) and log(6), we can extrapolate the value of log(5.5) by taking the mean of the results of log(5) and log(6). This value is in the interval [0.6989, 0.7782]. We then obtain 0.7386, whereas the actual value, to four decimal places, is approximately 0.7404. Therefore, we obtain an extrapolated value of log(5.5).