On 8/2/2013 12:58 PM, Richard Hennessy wrote:
>
>
> Is this okay? It is known that x is real and not much more, I think.
> Do you think the user should see, or would know, that n2 is the right
> way to enter this expression, not n1. See below for variables n1 and
> n2. What am I missing?
Basically, if the user types in n1,
>
>
> (%i19) n1:sqrt(x^4-2*x^2+1);
then he is typing two expressions. If he means one of them, he should
say which one.
It is unlikely he means a function with two corners, don't you think?
That's what you came up with, abs(x-1)*ab(x+1).
How can he say which one? Perhaps by specifying a point, or by
simplifying to x^2-1 or 1-x^2.