Describe the possible locations, in terms of quadrants or axes, for point a(x, y) if x and y satisfy the following condition
a. xy< 0 b. xy> 0 c. xy=0

Hello,

A: xy<0 ==>(x<0∧y>0) ∨(x>0∧y<0) ==>A(x,y)∈Quad II ∪ Quad IV

B: xy>0 ==>(x>0∧y>0) ∨(x<0∧y<0) ==>A(x,y)∈Quad I ∪ Quad III

C: xy=0 ==> x=0 ∨y=0 ==> A(x,y)∈ ox ∪ oy .