Question

对于集合M,N,定义M–N={x|x∈M,且x不包含于N},M*N=(M–N)∪(N–M),设A={t∣t=x2-3x

Answer 1

A={t∣t=x2-3x,x∈R}

=[-9/4,+∞)

B={x∣y=lg(-x)}=(-∞,0)

A-B=[0,+∞)

B-A=(-∞,-9/4)

A*B=(A-B)∪(B-A)=(-∞,-9/4)∪[0,+∞)

M*N=(M–N)∪(N–M)=M∪N–M∩N