Possible upper and lower bounds definition typo for real zeros of polynomial functions.
Shouldn't the signs of the final line of the division tableau be all positive for c > 0 to make it the upper bound? I don't think that merely having the same signs would suffice. They must all be positive, unless I am mistaken. My other textbooks state that they must all be positive for this upper bound. I did notice this effect on a practice problem as well where all signs were negative for the final line but it wasn't an upper bound. Problem #16 of the 3rd corrected edition. 4 gives all negatives but is not an upper bound. Thanks.