Question

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

Answer 1

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 .