# Symmetry in Mechanics Errata

Many thanks to the readers who have sent in corrections. If you find other errors, please let the author know!

P. 2: Sophus Lie was Norwegian, not French.

P. 3: There is a typo in Definition 1. The sum should be (v1 + v2, w1 + w2)

P. 6: On the third line replace "is" by "are".

P. 11: In the third displayed line (just below "What have we gained?") replace the first "m2" by "m1".

P. 26: On both sides of the first displayed equation and in the equation in Exercise 17, the factor of 1/t is incorrect and should be deleted.

P. 26: On the last line of this page, replace "R" by "R2".

P. 84: At the end of the last formula on the last line, replace "=g" by "=I".

P. 85: On the fourth line of the paragraph beginning "There is a standard recipe...", replace "M0" by "M".

P. 76, Ex. 72: Replace the punctured plane (R\0) with an open half plane. The solution to this exercise is incorrect: the proposed Hamiltonian function is not defined everywhere on the punctured plane.

P. 90: In Exercise 85, the first group should be (R^3,+), Euclidean three-space with addition.

P. 92: In the first displayed formula, the first equals sign should be replaced by a left arrow ($\mapsto$).

Pp. 124-5: In the displayed formula at the bottom of page 124, and in the first displayed formula on page 125, replace "Phi1" by "Phi0".

P. 132: In Figure 8.2, replace the label "pi" on the vertical axis by "sigma".

P. 159: In the second displayed equation, at the beginning of the expression between the equals signs, the first symbol should be the partial derivative of fwith respect to theta. In other words, insert an f into the formula.