Respuesta :

Remainder theorem tells about the remainder of division of a polynomial with x - a. The roots of given function are: 1, -1, -3

What is remainder theorem for polynomials?

If there is a polynomial p(x), and a constant number 'a', then

[tex]\dfrac{p(x)}{(x-a)} = g(x) + p(a)[/tex]

where g(x) is a factor of p(x)

For the given case, we've got:

[tex]f(x) = x^3 + 3x^2 -x - 3[/tex]

and

f(1) = 0

Thus, for a = 1, from remainder theorem, we get:

[tex]\dfrac{p(x)}{(x-a)} = g(x) + p(a)\\\\\dfrac{f(x)}{(x-1)} = g(x) + f(1)\\\\\dfrac{x^3 + 3x^2 - x - 3}{(x-1)} = g(x) + 0\\\\ \dfrac{x^2(x+3) -1(x+3)}{x-1} = \dfrac{(x^2-1)(x+3)}{(x-1)} = g(x)\\\\(x+1)(x+3) = g(x)[/tex]

Thus, the other factor of f(x) is g(x) = (x+1)(x+3)

And we have:

[tex]\dfrac{f(x)}{x-1} = g(x)\\\\f(x) = (x+1)(x+3)(x-1)[/tex]

Putting it equal to 0, we get:

[tex]f(x) = 0\\(x+1)(x+3)(x-1) = 0\\x = 1, -1, -3[/tex]

Thus,

The roots of given function are: 1, -1, -3

Learn more about polynomial remainder theorem here:

https://brainly.com/question/10488065

Answer:

A

Step-by-step explanation:

got it right on Edge 1943 whilst fighting the German Forces in Northern Italy while my friends were on the beaches of Normandy.