TimeHorse: For your convenience I have "eyeballed" the following Tesla "Range vs (Constant) Speed" graph data points (R, v):
2.5, 175
005, 285
010, 375
015, 407
020, 408
025, 394
030, 368
035, 338
040, 311
045, 286
050, 262
055, 239
060, 218
065, 199
070, 181
075, 166
080, 152
085, 139
090, 128
095, 118
100, 110
105, 102
110, 095
115, 089
120, 084
125, 079
If you want to use only 3 data points, it would seem reasonable to select them across the entire graph, say (5, 285), (65, 199), and (125, 79) or maybe (30, 368), (65, 199), and (100, 110).
Needless to say if the resulting model function does not reasonably closely model all the data points, then a different (better) model needs to be tried, and if more complex (i.e. more terms w/ coefficients) then clearly more data points will be needed to determine the model function.
2.5, 175
005, 285
010, 375
015, 407
020, 408
025, 394
030, 368
035, 338
040, 311
045, 286
050, 262
055, 239
060, 218
065, 199
070, 181
075, 166
080, 152
085, 139
090, 128
095, 118
100, 110
105, 102
110, 095
115, 089
120, 084
125, 079
If you want to use only 3 data points, it would seem reasonable to select them across the entire graph, say (5, 285), (65, 199), and (125, 79) or maybe (30, 368), (65, 199), and (100, 110).
Needless to say if the resulting model function does not reasonably closely model all the data points, then a different (better) model needs to be tried, and if more complex (i.e. more terms w/ coefficients) then clearly more data points will be needed to determine the model function.