College

We appreciate your visit to Find all rational zeros of the following function Then if necessary use the depressed equation to find all roots of the equation tex f x. This page offers clear insights and highlights the essential aspects of the topic. Our goal is to provide a helpful and engaging learning experience. Explore the content and find the answers you need!

Find all rational zeros of the following function. Then (if necessary) use the depressed equation to find all roots of the equation [tex]f(x)=0[/tex].

\[ f(x) = 3x^5 - 23x^4 + 55x^3 - 45x^2 + 2x + 8 \]

Select the correct choice below, and fill in the answer box if necessary.

A. The set of all zeros of the given function is [tex]\square[/tex] (Simplify your answer. Type an integer or a fraction. Type an exact answer, using radicals as needed. Use a comma to separate answers.)

B. There are no real zeros.

Answer :

To find all rational zeros of the polynomial function [tex]\( f(x) = 3x^5 - 23x^4 + 55x^3 - 45x^2 + 2x + 8 \)[/tex], we can use the Rational Root Theorem, which states that any rational root, [tex]\( \frac{p}{q} \)[/tex], of a polynomial is a factor of the constant term divided by a factor of the leading coefficient. In this case, our constant term is 8, and the leading coefficient is 3.

Step-by-Step Solution:

1. List all factors of the constant term (8):
Factors of 8: [tex]\( \pm 1, \pm 2, \pm 4, \pm 8 \)[/tex]

2. List all factors of the leading coefficient (3):
Factors of 3: [tex]\( \pm 1, \pm 3 \)[/tex]

3. Create all possible rational roots [tex]\( \frac{p}{q} \)[/tex]:
[tex]\[
\frac{\pm 1}{\pm 1}, \frac{\pm 1}{\pm 3}, \frac{\pm 2}{\pm 1}, \frac{\pm 2}{\pm 3}, \frac{\pm 4}{\pm 1}, \frac{\pm 4}{\pm 3}, \frac{\pm 8}{\pm 1}, \frac{\pm 8}{\pm 3}
\][/tex]
Simplifying, the possible rational roots are:
[tex]\[
\pm 1, \pm \frac{1}{3}, \pm 2, \pm \frac{2}{3}, \pm 4, \pm \frac{4}{3}, \pm 8, \pm \frac{8}{3}
\][/tex]

4. Test these possible roots in the polynomial [tex]\( f(x) \)[/tex].

We found that the polynomial has zeros at [tex]\( 1, 2, \)[/tex] and [tex]\( 4 \)[/tex]:

- For [tex]\( x = 1 \)[/tex]:
[tex]\[
f(1) = 3(1)^5 - 23(1)^4 + 55(1)^3 - 45(1)^2 + 2(1) + 8 = 3 - 23 + 55 - 45 + 2 + 8 = 0
\][/tex]
Hence, [tex]\( x = 1 \)[/tex] is a root.

- For [tex]\( x = 2 \)[/tex]:
[tex]\[
f(2) = 3(2)^5 - 23(2)^4 + 55(2)^3 - 45(2)^2 + 2(2) + 8 = 96 - 368 + 440 - 180 + 4 + 8 = 0
\][/tex]
Hence, [tex]\( x = 2 \)[/tex] is a root.

- For [tex]\( x = 4 \)[/tex]:
[tex]\[
f(4) = 3(4)^5 - 23(4)^4 + 55(4)^3 - 45(4)^2 + 2(4) + 8 = 3072 - 36864 + 14080 - 720 + 8 + 8 = 0
\][/tex]
Hence, [tex]\( x = 4 \)[/tex] is also a root.

5. List all the rational zeros we found:
[tex]\[
\boxed{1, 2, 4}
\][/tex]

These are all the rational zeros for the given polynomial function [tex]\( f(x) \)[/tex]. Thus, the set of all zeros of the given function is [tex]\( \{1, 2, 4\} \)[/tex].

Thanks for taking the time to read Find all rational zeros of the following function Then if necessary use the depressed equation to find all roots of the equation tex f x. We hope the insights shared have been valuable and enhanced your understanding of the topic. Don�t hesitate to browse our website for more informative and engaging content!

Rewritten by : Barada