Now I've given my talk, I have some more questions about dual numbers to investigate - some from here, and some from people who talked to me at #BigMathsJam.
- Apart from the duals and complex numbers, what other interesting degree-2 extensions of the reals exist? (HT George, didn't catch his surname)
- The dual numbers are the "first formal neighbourhood" of the reals - but what does that mean? (HT @RobJLow )
- The dual quaternions can be used to model mechanical linkages - see https://pure.hw.ac.uk/ws/portalfiles/portal/15726128/JMR161273_PURE.pdf How does that work? (HT @robinhouston )
- More generally, is there a connection between dual numbers and Lagrangian mechanics? How about Hamiltonian mechanics?
- I sketched a proof that the soul of f(x + ε) is f'(x) for any function f: R-> R that can be evaluated in finitely many arithmetic operations. Can we extend that to analytic functions? What about functions which are differentiable but not analytic? (HT @RobJLow )
- Let f be an analytic function, and g a polynomial approximation to f in a neighborhood of x. How well does the soul of g(x + ε) approximate f' in that neighbourhood? I guess that's the same as asking how well g' approximates f'...
#mathsjam