问答题
L(1/2)=0,L(1)=-1
问答题L(1/2)=0,L(1)=-1
L(i)=0,argL′(i)=π/2
问答题L(i)=0,argL′(i)=π/2
L(i)=0,L′(i)>0;
问答题L(i)=0,L′(i)>0;