Question

x^4-23x^2-8x+40

Answer 1

youre gonna have to provide some sor tof explanation is to what needs to be done with this

Answer 2

its a polynomial the answer is (x+1)(x+2)(x-1)(x-5) I need to show how to get there

Answer 3

well, the answer suggests that it is not factored by grouping; so theres a bit of trial and error involved

Answer 4

there are names strewn about like: rational roots test, decartes sign changes and the like

Answer 5

teh rational roots test on this one is simple enough since the first number is a 1; just factor out 40

1,2,4,5,8,10,20,40 .. i think thats all of the integer factors

now try them as roots and see which ones pass

Answer 6

ok thank u

Answer 7

with 2 sign changes to begin with; there are going to be either 2 or 0 positive roots according to descartes i believe

Answer 8

the answer also suggests the question said "factor"

Answer 9

yes im looking for interceptors

Answer 10

i have to wonder if this is the answer since the end numbers dont have a product of 40

Answer 11

(x+1)(x+2)(x-1)(x-5)

5.2.1.1 = 10, not 40

Answer 12

well these are the x interceptors

Answer 13

wolframalpha disagrees

http://www.wolframalpha.com/input/?i=x^4-23x^2-8x%2B40

Answer 14

hold on im sending a file

Answer 15

here

Answer 16

youre pretty good up til you say the "factors are"

its like you invented some fabricated results to stick in there instead of using what you found :)

Answer 17

the factors are the OPPPOSITE of the values you found

-(-4,-2,1,5) = 4,2,-1,-5 , insert these into the (x...) parts

(x+4)(x+2)(x-1)(x-5) is a better approximation

Answer 18

in otherwords, you probably typoed the 4 into a 1 :)

Answer 19

here

Answer 20

ok great thanks a lot this is the answers my intructor posted and he is giving me problems because i didnt show my work

Answer 21

the exact answers are NEAR these at best

Answer 22

here

Answer 23

ok thank u my friend

Answer 24

youre welcome :)