This test covers the Rational Root Theorem, complex zeros, polynomial graphs, asymptotes and inequalities. It has 9 questions worth 20 points. Allow 45 minutes, write intervals in interval notation, and show your work for full credit. Calculators are not needed.
- Grade: Precalculus
- Chapter: Polynomial and Rational Functions in Depth
- Common Core: A-APR.B.2, A-APR.B.3, F-IF.C.7c, F-IF.C.7d, N-CN.C.9
- Time: 45 minutes
- Total: 20 points (Question 1: 3 pts; Question 2: 2 pts; Question 3: 2 pts; Question 4: 2 pts; Question 5: 2 pts; Question 6: 3 pts; Question 7: 3 pts; Question 8: 2 pts; Question 9: 1 pt)
Question 1: Rational Root Theorem (3 points)
Let \(P(x)=2x^{3}+x^{2}-13x+6\).
- How many possible rational zeros does the Rational Root Theorem give? (1 point)
- Find all zeros of \(P\). (2 points)
Question 2: Complex zeros of a quartic (2 points)
Find all real and complex zeros of \(f(x)=x^{4}-16\).
Question 3: Build a polynomial (2 points)
Write a monic cubic polynomial with real coefficients that has zeros \(4\) and \(1+3i\). Give the answer in standard form.
Question 4: Read a polynomial graph (2 points)
The graph shows a polynomial \(g\) with a zero at \(-2\) and a zero at \(1\).
- State the multiplicity of each zero as odd or even. (1 point)
- State the least possible degree and the sign of the leading coefficient. (1 point)
Question 5: Asymptotes from a graph and a rule (2 points)
The graph shows \(f(x)=\frac{x^{2}-2x-3}{x+2}\).
- Find the equation of the vertical asymptote. (1 point)
- Find the equation of the slant asymptote. (1 point)
Question 6: Cubic inequality (3 points)
Solve \((x+3)(x-1)(x-4) > 0\) and write the answer in interval notation.
Question 7: Rational inequality (3 points)
Solve \(\frac{x-5}{x+1} \le 2\) and write the answer in interval notation.
Question 8: Average cost model (2 points)
The average cost per shirt for a team store is \(A(x)=\frac{15x+900}{x}\) dollars for \(x\) shirts.
- Find the horizontal asymptote of \(A\) and interpret it. (1 point)
- Find the smallest number of shirts for which the average cost is at most $20. (1 point)
Question 9: Conjugate zeros (1 point)
A polynomial with real coefficients has degree 5 and zeros \(2\), \(1-i\) and \(3i\). Write the other two zeros.
See every chapter on the Precalculus math page.


