We may note that letting the angle θj vary fromθj=π (minimum time) to θj=0 (maximum
time), we obtain the re-entrant curve in figure 4 for H = 30.9 m and V1 = 10.0 m s−1 as the
blue curve in figure 2. The maximum in this curve, giving the angle θ
∗ for which the maximum
circle is realized, can be obtained by setting the derivative of rj with respect to θj equal to zero.
This type of problem is similar to what has already been reported in [1, 2], so that the result
can be readily written as follows: