Question

已知集合A={y y=x²-4x+3} B={y y=-x²-2x+2} 求A∩B

Answer 1

y=x^2-4x+3=(x-2)^2-4+3=(x-2)^2-1

y>=-1

A={y/y>=-1}

y=-x^2-2x+2=-(x^2+2x-2)=-((x+1)^2-1-2)=-((x+1)^2-3)=-(x+1)^2+3

y