roots_blogPost.mcdx

Link to the blog post throws a "page not found" error.

Oops!  That might have been a timing thing.  I think it should be up now.

Yes, now it works.

Other points to be aware of are

• the difference between cubic_root(x^2) and (cubic_root(x))^2
• solving x^3=-8 is not the same as solving x=(-8)^(1/3)

One problem with Mathcad compared to other math programs is the inability to force results to domain real wheras possible. Assume modifier is faulty and ignored quite often and therefore not of much help.

IMHO Mathcad simply has far too few possibilities to control and steer results of calculations.

Power function, especially those with non-integer exponents and negative arguments, are not so simple as they might look on first sight. What I wonder is, why to Mathcad there is a difference between (-8)^(1/3) and cubic_root of -8. Should be the same (and in both cases NOT -2). Look at the screenshot of WolframAlpha below.

A Mathcad paradoxon which seems to fit in here is (f and g should be the same, but g yields real results only for selected negative values of x):

While I know the reason for this effect it can be quite confusing and annoying anyway.