∂A δq1 +∂A δq2 + ... = 0,  ∂B δq1 +∂B δq2 + ... = 0, &c.
∂q1 ∂q2∂q1 ∂q2

(29)

Introducing indeterminate multipliers λ, μ, ..., one for each of these equations, we obtain in the usual manner n equations of the type

d ∂T ∂T = Qr + λ∂A + μ∂B + ...,
dt ∂q˙r∂qr ∂qr ∂qr

(30)

in place of § 2 (10). These equations, together with (28), serve to determine the n co-ordinates q1, q2, ... qn and the m multipliers λ, μ, ....

When t does not occur explicitly in the relations (28) the system is said to be holonomic. The term connotes the existence of integral (as opposed to differential) relations between the co-ordinates, independent of the time.

Again, it may happen that although there are no prescribed relations between the co-ordinates q1, q2, ... qn, yet from the circumstances of the problem certain geometrical conditions are imposed on their variations, thus

A1δq1 + A2δq2 + ... = 0,   B1δq1 + B2δq2 + ... = 0, &c.,

(31)