Use synthetic division to determine whether the number k is an upper or lower bound (as specified for the real zeros of the function f).

k = 2; f(x) = 2x3 + 3x2 - 4x + 4; Lower bound?

Question

Use synthetic division to determine whether the number k is an upper or lower bound (as specified for the real zeros of the function f). 

k = 2; f(x) = 2x3 + 3x2 - 4x + 4; Lower bound?

anonymous · Answer

I got yes, is that correct?

anonymous · Answer

That is a different question.

0_0youscareme · Answer

oh okay

anonymous · Answer

Do you have any idea if my answer is correct?

amistre64 · Answer

what does it mean to be an lower bound?

anonymous · Answer

Alternation between non negative and non positive in signs, post division.

anonymous · Answer

I think

amistre64 · Answer

hmm, there is a thrm about it, can you post your materials thrm for it?

amistre64 · Answer

http://www.wtamu.edu/academic/anns/mps/math/mathlab/col_algebra/col_alg_tut39_zero2.htm this seems to be what you are learning about

amistre64 · Answer

2x3 + 3x2 - 4x + 4
         0        4      14      20
k=2| 2        7      10      24

since all the results are the same sign ... k=2 seems to be what type of bound?

amistre64 · Answer

2x3 + 3x2 - 4x + 4
           0        -4      2       4
k=-2|  2        -1     -2      8

when we let k=-2, the signs are not alternating are they ...

amistre64 · Answer

http://www.wolframalpha.com/input/?i=y%3D2x%5E3+%2B+3x%5E2+-+4x+%2B+4 notice that it only has one real root, and it is less than 2 ... it is even less then -2 if tha tmatters

anonymous · Answer

Okay, so it is not lower bound.