rational root theorem

[lhwalker]

I do not see the rational root theorem in the CCSS-M and assume students are not expected to memorize it. However, most textbooks have a unit where students must use it to list all possible rational zeros, and I see it included in several curriculum posted online. That might fall under A-APR.3 but I’m thinking what the students really need to know are the connections between zeros, factors, and remainders…not memorize the theorem or the formula x = p/q. Surely being aware of the theorem would be good but it doesn’t appear to me that we will be spending a lot of time with it if it isn’t mentioned in the standards…?

[Bill McCallum]

Lane, you have it exactly right here.

[tomergal]

Hello,

I just wanted to note that the rational root theorem seems necessary in order to solve problem number 19 in this PARCC Algebra 1 practice test.

[lhwalker]

In my thinking, if a student understands how to find the point of intersection with a calculator, the RRT would be inefficient for that student. The PARCC calculator policy is here: http://www.parcconline.org/assessments/administration

[tomergal]

Okay, interesting. I knew graphing calculators were allowed, but was not aware they were required for the test. Without a graphing calculator though, is there any way to solve this question without RRT?

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