product of factors question (1 Viewer)

[ausm8]

HI

Does anyone know how to write this as product of factors.

X^3+X^2-X-1. please show working.

thankyou

 

[jemsta]

x^3+x^2-x-1
= x^2(x+1)-(x+1)
=(x^2-1)(x+1)
=(x-1)(x+1)(x+1)


i hope thats right

 

[watatank]

HI

Does anyone know how to write this as product of factors.

X^3+X^2-X-1. please show working.

thankyou

let f(x) = x^3 + x^2 - x - 1

f(1) = 1 + 1 - 1 -1 = 0 ---> (x-1) is a factor
f(-1) = -1 + 1 -(-1) - 1 = 0 ---> (x+1) is a factor

so (x-1)(x+1)Q = x^3 + x^2 - x - 1

to find Q use long division, (x^3 + x^2 - x - 1) divided by (x^2 - 1)

 

[-pari-]

this is a 3u question

 

[Forbidden.]

this is a 3u question

i knew it