判断级数敛散性1-1/2!+1/3-1/4!+1/5-···
问题描述：
判断级数敛散性1-1/2!+1/3-1/4!+1/5-···
答
奇数项1,1/3,1/5,……>1/2+1/4+1/6+……=1/2(1+1/2+1/3+……)发散
偶数项1/2!+1/4!+1/6!……