Rational root theorem worksheet
Every polynomial here has one zero that is a fraction, which is what the rational root theorem is for: the top divides the constant, the bottom divides the leading coefficient. That gives a short list to test.
Select your difficulty
Pick more than one for a sheet that mixes them.
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Sigma Prep · sigmaprep.io/worksheets Name Rational ZerosDate Period Find all zeros. Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep |
Sigma Prep · sigmaprep.io/worksheets Name Rational ZerosAnswer keyVersion 1Date Period Find all zeros. Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep |
How to do these
- The top divides 6, the bottom divides 2.
- So the candidates are plus or minus 1, 2, 3, 6, 1/2 and 3/2.
- Testing finds -3/2 and 2.
The answer is or .
Where students go wrong
Only testing whole numbers. If the leading coefficient is not 1 then a fractional zero is likely, and a student who tries 1, 2 and 3 and gives up concludes wrongly that it does not factor.
Also called rational zero theorem, finding rational zeros or possible rational roots.