Digital Library of Mathematical Functions
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19 Elliptic IntegralsLegendre’s Integrals19.3 Graphics

Figure 19.3.11 (See in context.)

See accompanying text
Figure 19.3.11: \realpart{(\mathop{E\/}\nolimits\!\left(k\right))} as a function of complex k^{2} for -2\leq\realpart{(k^{2})}\leq 2, -2\leq\imagpart{(k^{2})}\leq 2. The real part is symmetric under reflection in the real axis. On the branch cut (k^{2}>1) it has the value k\mathop{E\/}\nolimits\!\left(1/k\right)+({k^{{\prime}}}^{2}/k)\mathop{K\/}%
\nolimits\!\left(1/k\right), with limit 1 as k^{2}\to 1+.