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?
1. x = 0
2.(x-y)^2 = (x^2) + (y^2)
3. xy = 0
(A) None
(B) 1 only
(C) 2 only
(D) 3 only
(E) 2 and 3