SOLUTION: List all rational zeros that are possible according to the Rational Zero Theorem The following function is given: f(X)=x3-5x2-4x+20 I am assuming that I look for the leading c

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Question 1155272: List all rational zeros that are possible according to the Rational Zero Theorem
The following function is given: f(X)=x3-5x2-4x+20
I am assuming that I look for the leading coefficient first
Then possible rational zeros Factors of the constant terms
Factors of the leading coefficient
I am going to assume that the constant term is 20.
The leading Coefficient would be 1, 5,-5,2-2,4.-4,20, -20
Found 2 solutions by MathLover1, ikleyn:
Answer by MathLover1(20850)   (Show Source): You can put this solution on YOUR website!


the Rational Zero Theorem tells us that if is a zero of , then is a factor of and is a factor of .
The factors of are ± and
the factors of are ± ,± , ±, ±,± ,±.
The possible values for are:
±, ±, ±, ±,±,±
These are the rational zeros for the function.
We can determine which of the possible zeros are by substituting these values for in .
do it and you will see that are:
Answer by ikleyn(52879)   (Show Source): You can put this solution on YOUR website!
.

In your list, you missed -1, 10 and - 10.


Notice, that in your problem, the leading coefficient is 1 (one, ONE), and it makes the solution much EASIER.


The better way is to present your list in this form


    +/-1, +/-2, +/-4, +/-5, +/-10, +/-20.


When you present in this form, you are (almost) guaranteed from missing the terms.

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

            Notices and guidelines 

    In this problem, the leading coefficient is 1 (at x^3).

    The constant term is 20.

    You must list all the numbers  +/- .



IGNORE  THE  POST  BY  @MathLover1,  since she presented  TOTALLY  WRONG  solution.

Ignore it for your safety (!) (!) (!)


Dear @MathLover1,  in my view,  it is  ABSOLUTELY  INAPPROPRIATE  for a tutor to consult students/visitors
in a level as you did it in this case  (and in many other cases I observed).

I know that you are able to consult satisfactory/successfully on many simple level problems.

Do it in those areas/topics,  where you are confident,  and do not go outside,  where you have no enough knowledge/expertise.

One more advise:  CHECK  yourself,  using both the formal checks and the common sense.



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