Quick help please!! The value -1 is a lower bound for the zeros of the function shown below.. f(x)=x^4+x^3-11x^2-9x+18. True or false

Question

ranga · Answer

Use synthetic division to divide the polynomial by (x - (-1)) = (x + 1).
If the last line containing the quotient and remainder alternate in sign then -1 is the lower bound.

anonymous · Answer

ok so it is false then

anonymous · Answer

right?

ranga · Answer

Haven't done the division myself as I am answering other people's question too.

ranga · Answer

yeah, looks like false.

anonymous · Answer

thanks!

ranga · Answer

you are welcome.  I did the division and it It is false.

ranga · Answer

Just in case:  Dividing the polynomial by (x+1)  means doing the synthetic division by -1  (not +1).  
The answer is still false but I just thought I should make the division part clear.