It turns out he's claiming they're different if x^2 is interpreted as squaring each element in the interval x, while x * x is interpreted as a cross product: the interval obtained by multiplying all pairs of elements in the interval. But I haven't ever seen anyone use x^2 to mean pointwise squaring on an interval x. Is that some kind of standard notation?
It turns out he's claiming they're different if x^2 is interpreted as squaring each element in the interval x, while x * x is interpreted as a cross product: the interval obtained by multiplying all pairs of elements in the interval. But I haven't ever seen anyone use x^2 to mean pointwise squaring on an interval x. Is that some kind of standard notation?