How do you use synthetic division to find if x+1 is a factor for $f(x)=2x^3+5x^2-x-4$ ?

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Answer 1 · 2015-09-24T18:22:26

Using synthetic division as shown below would result in a zero remainder.

If: $x+1$ is a factor then: $x=-1$ is a root/zero of the polynomial:

$f(x)=2x^3+5x^2-x-4$

hence synthetic division should produce a zero remainder.

$.......... 2 ........ 5 ...... -1 ...-4$
$-1 | darr...-2......-3.........4$
$.......... 2.........3...... -4........0=>$ Remainder

Quotient $=2x^2+3x-4$

How do you use synthetic division to find if x+1 is a factor for f(x)=2x^3+5x^2-x-4f(x)=2x^3+5x^2-x-4?