where A is a constant. From this equation we readily derive the formulae
(10)
,
and
(11)![{\displaystyle f={\frac {2}{\gamma -1}}A\gamma ^{1/2}\theta ^{\gamma /2}}](https://wikimedia.org/api/rest_v1/media/math/render/svg/cbf45793cfebc29fd9a7e0d489f702a9423e59ac)
.
Thus for the case under consideration
(12)
and
.
Moreover we readily verify from the foregoing that
(13)
.
Combining equations (7), (12) and (13) we obtain the equations quoted in the text.