Brandon's notes

[moorepants]

• Confusing reference frames with coordinate systems
• When I say reference frame it has three orthogonal unbounded unit vectors attached to it.
• Dynamic symbols first appeared: need explanation showing the difference in them an regular symbols.
• Flipping to the 7th notebook, you may think that mass_matrix is not mass_matrix_full (explain the difference in mass matrix full and mass matrix). Change the language to be consitent.
• Don't say cross product is only in 3D
• change to %matplotlib notebook