Question

1-1/2+1/3-1/4+1/5-1/6+1/7-1/8+1/9-1/10+1/11-1/12+1/13-1/14的无

Answer 1

ln(1+x)=x-1/2x²+1/3x³-1/4x^4+1/5x^5+…………

的收敛域为（-1,1]

当x=1时,就有：

1-1/2+1/3-1/4+1/5-1/6+………………=ln2