Browse · MATH
Printjmc
algebra intermediate
Problem
A polynomial of degree four with leading coefficient 1 and integer coefficients has two real zeros, both of which are integers. Which of the following can also be a zero of the polynomial?
(A)
(B)
(C)
(D)
(E)
(A)
(B)
(C)
(D)
(E)
Solution
If and are the integer zeros, the polynomial can be written in the form The coefficient of , , is an integer, so is an integer. The coefficient of , , is an integer, so is also an integer. Applying the quadratic formula gives the remaining zeros as Answer choices (A), (B), (C), and (E) require that , which implies that the imaginary parts of the remaining zeros have the form . This is true only for choice . Note that choice (D) is not possible since this choice requires , which produces an imaginary part of the form , which cannot be .
Final answer
\text{(A)}