Get the answers you need at Westonci.ca, where our expert community is dedicated to providing you with accurate information. Get expert answers to your questions quickly and accurately from our dedicated community of professionals. Connect with a community of professionals ready to help you find accurate solutions to your questions quickly and efficiently.

Question 5 of 5:

State the possible rational zeros for each function. Then find all rational zeros.

[tex]\[ f(x) = 4x^3 - 12x^2 - 35x - 12 \][/tex]

Sagot :

To determine the possible rational zeros of the polynomial [tex]\( f(x) = 4x^3 - 12x^2 - 35x - 12 \)[/tex], we use the Rational Root Theorem. This theorem states that any rational zero, [tex]\(\frac{p}{q}\)[/tex], of a polynomial with integer coefficients is such that:

- [tex]\(p\)[/tex] is a factor of the constant term (the term without [tex]\(x\)[/tex]), which is [tex]\(-12\)[/tex].
- [tex]\(q\)[/tex] is a factor of the leading coefficient (the coefficient of the term with the highest power of [tex]\(x\)[/tex]), which is [tex]\(4\)[/tex].

### Step 1: Identify the factors of the constant term and leading coefficient

- The factors of [tex]\(-12\)[/tex] (constant term) are: [tex]\(\pm 1, \pm 2, \pm 3, \pm 4, \pm 6, \pm 12\)[/tex].
- The factors of [tex]\(4\)[/tex] (leading coefficient) are: [tex]\(\pm 1, \pm 2, \pm 4\)[/tex].

### Step 2: Generate all possible rational zeros

Using the factors identified, we can list all possible rational zeros [tex]\(\frac{p}{q}\)[/tex]:

[tex]\[ \frac{p}{q} = \pm 1, \pm 2, \pm 3, \pm 4, \pm 6, \pm 12, \pm \frac{1}{2}, \pm \frac{3}{2}, \pm \frac{1}{4}, \pm \frac{3}{4} \][/tex]

Putting them all together in a sorted order, we get the following possible rational zeros:
[tex]\[ -12, -6, -4, -3, -2, -\frac{3}{2}, -1, -\frac{3}{4}, -\frac{1}{2}, -\frac{1}{4}, \frac{1}{4}, \frac{1}{2}, \frac{3}{4}, 1, \frac{3}{2}, 2, 3, 4, 6, 12 \][/tex]

### Step 3: Test each potential rational zero to find the actual rational zeros

By evaluating [tex]\( f(x) \)[/tex] at each of the possible rational zeros, we determine which ones are actual zeros:

[tex]\[ f(x) = 4x^3 - 12x^2 - 35x - 12 \][/tex]

After testing each potential rational zero, we find that the actual rational zeros are:

[tex]\[ -\frac{3}{2} \][/tex]

So, the only rational zero of the polynomial [tex]\( f(x) = 4x^3 - 12x^2 - 35x - 12 \)[/tex] is [tex]\(-\frac{3}{2}\)[/tex].

### Step 4: Find all zeros of the polynomial

To find all zeros of the polynomial, we solve [tex]\( f(x) = 0 \)[/tex]. Besides the rational zero [tex]\(-\frac{3}{2}\)[/tex], there might be other zeros. Solving the polynomial equation, we obtain:

[tex]\[ -\frac{3}{2}, \frac{9}{4} - \frac{\sqrt{113}}{4}, \frac{9}{4} + \frac{\sqrt{113}}{4} \][/tex]

### Summary

- Possible rational zeros: [tex]\([-12, -6, -4, -3, -2, -3/2, -1, -3/4, -1/2, -1/4, 1/4, 1/2, 3/4, 1, 3/2, 2, 3, 4, 6, 12]\)[/tex]
- Actual rational zeros: [tex]\([-3/2]\)[/tex]
- All zeros: [tex]\([-3/2, 9/4 - \sqrt{113}/4, 9/4 + \sqrt{113}/4]\)[/tex]