# Straight line, fractional difference

by CarEnthusiast
Tags: line, straight
 P: 44 Do they really "end up equalling the same thing"? You certainly haven't shown that they do - perhaps you should try to manipulate your answers to "Method 1" and "Method 2" to check whether or not this is true. The "fractional difference" between two numbers is the difference between them divided by the "reference" number - which in this case would be whichever of the two methods correctly predicts the windless speed. (I.e., $$\frac{\text{other method} - \text{windless speed}}{\text{windless speed}}$$ )