
The local truncation error incurred in the ith integration interval is estimated from the difference of
Equations 6.167 and 6.166. Thus,
Estimate of (e
T
)
i
¼ T
1
360
k
1
128
4275
k
3
2197
75240
k
4
þ
1
50
k
5
þ
2
55
k
6
(6:168)
Example 6.6 illustrates the use of RK–Fehlberg integration, specifically, the RK-4 and RK-5
methods previously described.
Example 6.6
A motor boat is being driven across a river L ft wide to the opposite side as shown in Figure 6.11.
The boat departs from point 0, the origin of an x–y coordinate system, attempting to reach a point
H ft upstream. The boat travels at a constant speed v
b
mph relative to the water that flows
downstream at a speed of v
r