已知集合A={y=x^2-2x,x∈R},B={z=x^2+6x+8,x∈R}求A∩B
问题描述：
已知集合A={y=x^2-2x,x∈R},B={z=x^2+6x+8,x∈R}求A∩B
答
A={y=x^2-2x,x∈R},B={z=x^2+6x+8,x∈R}
for A∩B =>
x^2-2x = x^2+6x+8
8x = -8
x = -1
for x=-1
y=1+2 = 3
A∩B = {3} #