已知A={X/X的平方+2X+P=0} B={X/X>0} 且A交B是空集,求P的取值范围?

A={x|x^2+2x+P=0}
B={x|x>0}
if A= ø => A∩B＝ø
for no real roots
△< 0
4-4p1
OR
roots of equation ≤0
roots of equation:x^2+2x+P=0
x =( -2+√4-4P )/2 or ( -2-√4-4P )/2
if ( -2+√4-4P )/2 ≤0
=> P ≥0
and ( -2-√4-4P )/2 ≤0
=> P ≤ 0
ie P =0
for A∩B＝ø
P=0 or P>1 #