R = [Tau] - [kappa][chi]` - [kappa]'[chi]`' - [kappa]"[chi]`" - ..., (3)

and imagine R to be expressed by means of (2) as a quadratic function

of q`1, q`2, ... q`_m, [kappa], [kappa]', [kappa]", ... with

coefficients which are in general functions of the co-ordinates q1,

q2, ... q_m, then, performing the operation [delta] on both sides, we

find

dPR dPR dPR dP[Tau] dP[Tau]

-----[delta]q`1 + ... + ---------[delta][kappa] + ... + ----[delta]q1 + ... = -------[delta]q`1 + ... + -------[delta]q1 + ...

dPq`1 dP[kappa] dPq1 dPq`1 dPq1

dP[Tau] dP[Tau]

+ --------[delta][chi]` + ... + --------[delta]q1 + ... - [kappa][delta][chi]` - [chi]`[delta][kappa] - .... (4)

dP[chi]` dP[chi]1

Encyclopaedia Britannica, 11th Edition, "Dyer, Sir Edward" to "Echidna" Volume 8, Slice 9 · 第 32 / 84 题