Mathematics > Standard Multiple Choice
Read the following SAT test question and then click on a button to select your answer.
If (x + y)^2 = (x^2) + (y^2), which of the following statements must also be true?
I. x = 0
II.(x-y)^2 = (x^2) + (y^2)
III. xy = 0
(A) None
(B) I only
(C) II only
(D) III only
(E) II and III