What are the zeros of the polynomial function? f(x)=x^4+2x^3-16x^2-2x+15

x^4 + 2x^3 - 16x^2 - 2x + 15

We can use the rational roots theorem to find some of the possible roots, and after finding just one root, we can simplify this polynomial.

List factors of 15:

1, 3, 5, 15.

List factors of 1:

1.

Our possible rational factors are:

+/- 1, +/- 3, +/- 5, +/- 15.

To find factors, we can use the remainder theorem.

Replace all x values with 1.

1^4 + 2(1)^3 - 16(1)^2 - 2(1) + 15 = 0

Because the answer is zero, it means that 1 is a root.

We can divide this polynomial by x - 1 to find a simplified form.

After dividing, our quotient is: x^3 + 3x^2 - 13x - 15

We can continue finding factors by using the rational roots theorem. Once we have only three terms, we can try to factor using the AC method.

Our next possible root is -1.

(-1)^3 + 3(-1)^2 - 13(-1) - 15 = 0

We know that -1 is also a root, and so we can divide the polynomial by x + 1.

After diving we're left with x^2 + 2x - 15.

Now, we can try to factor using the AC method.

List factors of -15.

1 * -15

-1 * 15

3 * -5

-3 * 5 (these digits satisfy the criteria.)

Split the middle term.

x^2 - 3x + 5x - 15

Factor binomials.

x(x - 3) + 5(x - 3)

Rearrange binomials.

(x + 5)(x - 3)

Add in the two factors we already factored out.

(x - 1)(x + 1)(x + 5)(x - 3)

y=1/4x-4

step-by-step explanation: