The equations of constraint for the rolling disk, Eqs. (1.39), are special cases of general linear differential equations of constraint of the form
i=1∑ngi(x1,…,xn)dxi=0.
A constraint condition of this type is holonomic only if an integrating function f(x1,…,xn) can be found that turns it into an exact differential. Clearly the function must be such that
∂xj∂(fgi)=∂xi∂(fgj)
for all i=j. Show that no such integrating factor can be found for either of Eqs. (1.39).