Re: "table of sign" question re: differentiation

ok thanks for that, yeah that was a typo in my 1st example.
So what happens though if you have a combination of positives and
negatives in a column in the table
ie.  2 positives and a negative or 2 negatives and a positive? do you
then have to just work it out for f'(x)

ie when x=2 then

15x^2 = 60 (positive)
1 + x = 3 (postive)
1 - x = -1 (negative)

f' ' (2) when calculated is negative