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