Question

Which of the following is a requirement for a trinomial to be factored as a perfect square?
A. The coefficient for the x term must be twice the square root of the first term.
B. The coefficient for the x term must be twice the square root of the last term.
C. The coefficient for the x term must be twice the product of the square roots of the first and last terms.
D. The coefficient for the x term must be half the product of the square roots of the first and last terms.