f(x) = ln(1+x)
f'(x) = 1/(1+x)
f''(x) = -1/(1+x)^2
f'''(x) = 2/(1+x)^3
f^(n)(x) = [(-1)^(n+1)]n!/(1+x)^(n+1)
验证函数f(x)=In(1+x)的n阶麦克劳林公式.
f(x) = ln(1+x)
f'(x) = 1/(1+x)
f''(x) = -1/(1+x)^2
f'''(x) = 2/(1+x)^3
f^(n)(x) = [(-1)^(n+1)]n!/(1+x)^(n+1)