Find the bounds on the real zeros of the following function. Please show your work so I will understand it. f(x)= x^4+2x^3-4x^2+x-1 Find the bounds on the real zeros of the following function. Please show your work so I will understand it. f(x)= x^4+2x^3-4x^2+x-1 @Mathematics

Question

turingtest · Answer

can you see a root offhand using the rational root theorem?

turingtest · Answer

or just by looking? one of them is pretty obvious

anonymous · Answer

i don't remember much, but i believe all real roots will be within -5 and 5.

turingtest · Answer

yes -5 and 5 will be the bounds, but showing the work will be rather tedious.

anonymous · Answer

yea i see 5 and -5...i guess there really isnt any work to show, huh? lol

turingtest · Answer

No there is, it just takes forever in this online format. I will describe the process if you like. would you like me to try?

turingtest · Answer

or just read this i guess http://www.wtamu.edu/academic/anns/mps/math/mathlab/col_algebra/col_alg_tut39_zero2.htm

anonymous · Answer

the way i was taught was to look at the coefficients. in this case

1 2 -4 1 -1

drop the first one

2 -4 1 -1

make all positive

2 4 1 1

find the largest one and add 1

4 + 1 = 5

add them

2+4+1+1=8

since 5 < 8, we take 5. thus the boundaries are -5 and 5