How do you use the factor theorem to determine whether 3x+1 is a factor of f(x)= 3x^4 -11x^3 - 55x^2 + 163x + 60f(x)=3x411x355x2+163x+60?

1 Answer
Jun 13, 2018

3x+13x+1 is a factor of f(x)f(x)

Explanation:

Let's define f(c)f(c) to be equal to 3x+13x+1. Thus, the factor theorem tells us if f(c)=0f(c)=0, then 3x+13x+1 is a factor of our polynomial f(x)f(x).

Let's set f(c)f(c) equal to zero. We get

3x+1=03x+1=0

=>3x=-13x=1

=>color(blue)(x=-1/3)x=13

Now, let's plug this value into our polynomial. This is a hairy problem, so let's not be ashamed to use a calculator. I did but had issues uploading the image, but this evaluates to zero.

Since it evaluated to zero, 3x+13x+1 is a factor of f(x)f(x).

Hope this helps!