# When would linear extrapolation be more useful than linear interpolation?

##### 1 Answer

Feb 21, 2015

Some definitions first:

**Linear interpolation** : finding a point between two known data points under the assumption that the domain and range are linked by some linear function.

**Linear extrapolation** : finding a point beyond the known set of data points.

As the second example shows, linear extrapolation can be used by establishing a tangent line to the last known data point even when the data points are non-linear.