Template:Math/EQ QminusHalf01

	$Q_{-\frac{1}{2}}(z)$	$=$	$\sqrt{\frac{2}{z+1}}K\left(\sqrt{\frac{2}{z+1}}\right)$	for example …	$Q_{-\frac{1}{2}}(\cosh \eta )$	$=$	$2e^{-\eta /2}K(e^{-\eta })$
Abramowitz & Stegun (1995), p. 337, eq. (8.13.3)					Abramowitz & Stegun (1995), p. 337, eq. (8.13.4)