已知xy≠0且根号4x^2y^2=-2xy,则有()
问题描述:
已知xy≠0且根号4x^2y^2=-2xy,则有()
A.xy0 C.x>0,y>0 D.x
答
√4x²y²=√(2xy)²=|2xy|=-2xy
所以xy