(a + b)' = a' + b'
(a - b)' = a' - b'
(a b)' = a'b + a b'
(a/b)' = (a'b - a b')/b^2
f(g(t))' = f'(g(t)) g'(t)
rules for differentiation of functions like
(these can be implemented using a table
look up)