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2 votes
The number 4 is an upper bound for the set of roots of this polynomial

function.


f(x) = 3x4 – 5x? – 5x2 + 5x+ 2


A. True


B. False

1 Answer

2 votes

Answer:

The answer is **B. False**. The number 4 is not an upper bound for the set of roots of this polynomial function.

To see why, we can use the **rational root theorem**, which states that if a polynomial function has rational roots, then they must be of the form p/q, where p is a factor of the constant term and q is a factor of the leading coefficient.

In this case, the constant term is 2 and the leading coefficient is 3, so the possible rational roots are:

±1, ±2, ±1/3, ±2/3

We can use **synthetic division** to test each of these possible roots and see if they give a remainder of zero, which means they are actual roots.

If we try 4, we get:

| 4 | 3 | -5 | -5 | 5 | 2 |

|---|---|----|----|---|---|

| | | 12 | 28 | 92 | 388 |

|---|---|----|----|---|---|

| | 3 | 7 | 23 | 97 | 390 |

The remainder is 390, which is not zero, so 4 is not a root of the polynomial function.

Therefore, 4 is not an upper bound for the set of roots of this polynomial function.

: [Rational Root Theorem]

: [Synthetic Division]

Explanation:

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