Get expert advice and community support for all your questions on IDNLearn.com. Discover reliable and timely information on any topic from our network of knowledgeable professionals.

Question 15 of 46

When using the rational root theorem, which of the following is a possible root of the polynomial function below?

[tex]\[ F(x) = 3x^3 - x^2 + 4x + 5 \][/tex]

A. -7
B. [tex]\(\frac{4}{3}\)[/tex]
C. [tex]\(-\frac{5}{3}\)[/tex]
D. 6


Sagot :

To solve the problem of finding a possible rational root for the polynomial [tex]\( F(x) = 3x^3 - x^2 + 4x + 5 \)[/tex] using the Rational Root Theorem, follow these steps:

1. Identify the constant term and the leading coefficient of the polynomial:

- The constant term is the term without any [tex]\( x \)[/tex], which is 5.
- The leading coefficient is the coefficient of the term with the highest power of [tex]\( x \)[/tex], which is 3.

2. List the possible rational roots:

According to the Rational Root Theorem, any rational root of the polynomial, expressed as [tex]\( \frac{p}{q} \)[/tex], where [tex]\( p \)[/tex] is a factor of the constant term and [tex]\( q \)[/tex] is a factor of the leading coefficient, must be among the following:

- Factors of the constant term (5): [tex]\( \pm 1, \pm 5 \)[/tex]
- Factors of the leading coefficient (3): [tex]\( \pm 1, \pm 3 \)[/tex]

Hence, the possible rational roots are:

- [tex]\( \pm \frac{p}{q} \)[/tex] where [tex]\( p \)[/tex] is a factor of 5 and [tex]\( q \)[/tex] is a factor of 3.

This results in the possible roots being: [tex]\( \pm 1, \pm \frac{1}{3}, \pm 5, \pm \frac{5}{3} \)[/tex].

3. Match the given options to the possible roots:

Given options are:
- A. [tex]\(-7\)[/tex]
- B. [tex]\(\frac{4}{3}\)[/tex]
- C. [tex]\(-\frac{5}{3}\)[/tex]
- D. 6

4. Compare the options with the list of possible roots:

- [tex]\(-7\)[/tex] is not in the list of possible roots.
- [tex]\(\frac{4}{3}\)[/tex] is not in the list of possible roots.
- [tex]\(-\frac{5}{3}\)[/tex] is in the list of possible roots.
- 6 is not in the list of possible roots.

Upon comparison, we find that the only option from the given choices that matches one of the possible rational roots is:

C. [tex]\(-\frac{5}{3}\)[/tex]

Thus, the possible root of the polynomial [tex]\( F(x)=3x^3-x^2+4x+5 \)[/tex] among the given options is [tex]\( -\frac{5}{3} \)[/tex].