若集合A={x|x/x+1>1},B={y|y=x²+x,x∈R},则A∪B=?
问题描述:
若集合A={x|x/x+1>1},B={y|y=x²+x,x∈R},则A∪B=?
答
x/(x+1)>1,即x/(x+1)-1>0,-1/(x+1)>0,则x
若集合A={x|x/x+1>1},B={y|y=x²+x,x∈R},则A∪B=?
x/(x+1)>1,即x/(x+1)-1>0,-1/(x+1)>0,则x