SOLUTION: 1. Given the polynomial f(x) = 4x^4 + 5x^3 + 7x^2 - 34x + 8 (a) By using the Rational Zero Theorem, list all possible rational zeros of the given polynomial.

Algebra.Com
Question 149741: 1. Given the polynomial f(x) = 4x^4 + 5x^3 + 7x^2 - 34x + 8

(a) By using the Rational Zero Theorem, list all possible rational zeros of the given polynomial.








(b) Find all of the zeros of the given polynomial. Show the procedure





Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!
a)


Any rational zero can be found through this equation

where p and q are the factors of the last and first coefficients


So let's list the factors of 8 (the last coefficient):



Now let's list the factors of 4 (the first coefficient):



Now let's divide each factor of the last coefficient by each factor of the first coefficient









Now simplify

These are all the distinct rational zeros of the function that could occur










b)


Now let's use synthetic division to test each possible zero:




Let's make the synthetic division table for the function given the possible zero :
1/2|457-348
| 27/221/4-115/8
4721/2-115/4-51/8

Since the remainder (the right most entry in the last row) is not equal to zero, this means that is not a zero of


------------------------------------------------------


Let's make the synthetic division table for the function given the possible zero :
1/4|457-348
| 13/217/8-255/32
4617/2-255/81/32

Since the remainder (the right most entry in the last row) is not equal to zero, this means that is not a zero of


------------------------------------------------------


Let's make the synthetic division table for the function given the possible zero :
2|457-348
| 8266664
413333272

Since the remainder (the right most entry in the last row) is not equal to zero, this means that is not a zero of


------------------------------------------------------


Let's make the synthetic division table for the function given the possible zero :
4|457-348
| 16843641320
421913301328

Since the remainder (the right most entry in the last row) is not equal to zero, this means that is not a zero of


------------------------------------------------------


Let's make the synthetic division table for the function given the possible zero :
8|457-348
| 32296242419120
437303239019128

Since the remainder (the right most entry in the last row) is not equal to zero, this means that is not a zero of


------------------------------------------------------


Let's make the synthetic division table for the function given the possible zero :
-1|457-348
| -4-1-640
416-4048

Since the remainder (the right most entry in the last row) is not equal to zero, this means that is not a zero of


------------------------------------------------------


Let's make the synthetic division table for the function given the possible zero :
-1/2|457-348
| -2-3/2-11/4147/8
4311/2-147/4211/8

Since the remainder (the right most entry in the last row) is not equal to zero, this means that is not a zero of


------------------------------------------------------


Let's make the synthetic division table for the function given the possible zero :
-1/4|457-348
| -1-1-3/271/8
446-71/2135/8

Since the remainder (the right most entry in the last row) is not equal to zero, this means that is not a zero of


------------------------------------------------------


Let's make the synthetic division table for the function given the possible zero :
-2|457-348
| -86-26120
4-313-60128

Since the remainder (the right most entry in the last row) is not equal to zero, this means that is not a zero of


------------------------------------------------------


Let's make the synthetic division table for the function given the possible zero :
-4|457-348
| -1644-204952
4-1151-238960

Since the remainder (the right most entry in the last row) is not equal to zero, this means that is not a zero of


------------------------------------------------------


Let's make the synthetic division table for the function given the possible zero :
-8|457-348
| -32216-178414544
4-27223-181814552

Since the remainder (the right most entry in the last row) is not equal to zero, this means that is not a zero of



====================================

Since none of the possible rational roots are actual roots, this means that the polynomial either has irrational roots or complex roots.

RELATED QUESTIONS

1. Use synthetic division to divide the polynomial 2x^3 + 7x^2 – 5 by 3+x and write the... (answered by jim_thompson5910)
Use the Rational Zero Theorem to list all possible rational zeros for the given... (answered by solver91311)
List the possible rational zeros of f using the rational zero theorem. f(x) = x^3 +... (answered by richard1234)
8) Use the Rational Zero Theorem to list all possible rational zeros for the given... (answered by MathLover1)
List all possible rational zeros of f using the rational zero theorem. Then find all the... (answered by nyc_function)
Please help me, I'm so confused! List the possible rational zeros of the function... (answered by jim_thompson5910)
Using the rational zero theorem to list all possible rational zeros for each polynomial... (answered by Big Poop)
I have a question that states: use the Rational Zero Theorem to find all possible... (answered by scianci)
Use the rational zero theorem to list all possible rational zeros for the given function. (answered by DrBeeee)