SOLUTION: 5. Use the rational zeros theorem to list the potential rational zeros of the polynomial function. Do not attempt to find the zeros. f (x) = 2x^11−x^9+ 3x^8 + 28 Find

Algebra ->  Inequalities -> SOLUTION: 5. Use the rational zeros theorem to list the potential rational zeros of the polynomial function. Do not attempt to find the zeros. f (x) = 2x^11−x^9+ 3x^8 + 28 Find       Log On


   



Question 1089810: 5.
Use the rational zeros theorem to list the potential rational zeros of the polynomial function. Do not attempt to find the zeros.
f (x) = 2x^11−x^9+ 3x^8 + 28
Find the potential Rational zeros.


A.
−1, 1, −2, 2, −4, 4, −7, 7, −14, 14, −28, 28, −1/2, 1/2, −7/2, 7/2


B.
−1, 1, −2, 2, −4, 4, −7, 7, −28, 28, −1/2, 1/2, −1/28, 1/28


C.
−1, 1, −2, 2, −4, 4, −7, 7, −28, 28, −1/2, 1/2, −7/2, 7/2, −1/28, 1/28


D.
−1, 1, −2, 2, −4, 4, −7, 7, −14, 14, −28, 28, −1/2, 1/2, −1/28, 1/28
Choose A, B, C, OR D. (SHOW WORK)

Found 2 solutions by ikleyn, math_helper:
Answer by ikleyn(52847) About Me  (Show Source):
You can put this solution on YOUR website!
.
Use the rational zeros theorem to list the potential rational zeros of the polynomial function. Do not attempt to find the zeros.
f (x) = 2x^11−x^9+ 3x^8 + 28
Find the potential Rational zeros.
A.
−1, 1, −2, 2, −4, 4, −7, 7, −14, 14, −28, 28, −1/2, 1/2, −7/2, 7/2    <<<---=== This answer is correct.


B.
−1, 1, −2, 2, −4, 4, −7, 7, −28, 28, −1/2, 1/2, −1/28, 1/28


C.
−1, 1, −2, 2, −4, 4, −7, 7, −28, 28, −1/2, 1/2, −7/2, 7/2, −1/28, 1/28


D.
−1, 1, −2, 2, −4, 4, −7, 7, −14, 14, −28, 28, −1/2, 1/2, −1/28, 1/28

Choose A, B, C, OR D. (SHOW WORK)

On rational root theorem see this Wikipedia article

https://en.wikipedia.org/wiki/Rational_root_theorem


The potential roots are all integer divisors of the constant term 28, AND all fractions of dividing these divisors by 2.



Answer by math_helper(2461) About Me  (Show Source):
You can put this solution on YOUR website!
All the potential zeros have the form p/q where p is a factor of the constant term and q is a factor of the leading coefficient. Since the constant term is 28, p can take on +/- { 1,2,4,7,14,28}. Since the leading coefficient is 2, q can take on values +/-{1,2}

Answer A is the only one that has all p/q that fit these constraints.
[ It is easy to eliminate the other choices because they each have +/- 1/28 ].