Question

已知全集U=R,A={yy|y=x^2+4x+1｝,B=｛y|y=-x^2+2x+5｝,求A∩B与CuBUA

Answer 1

A

y=(x+2)²-3≥-3

B

y=-(x-1)²+6≤6

所以

A∩B

={y|-3≤y≤6}

CuB∪A

={y|y≥-3}