Fig. 12

$\theta (P)$ versus A for $P=10.5$ (solid) and $P=13$ (dashed), along curves of extrema obtained by solving the BVP. The two curves coincide on the low, horizontal branch near $\theta (P)=5$. For each P, note the existence of multiple extrema for a small interval of A values as well as the occasional abrupt increases in θ, corresponding to spike addition.