[问答题]
1. By successive differentiation fj3qs m p2tk).find the first five non-zero terms iug 2xc jppwc+z)o99q* )e6uman the Maclaur6pxagp9*zcmeu2 qo)w u +cj9)in series for $ f(x)=(2-2 x) \ln (1-x)+2 x$ .
2. Deduce that, for $n \geq 2 $, the coefficient of x^{n} in this series is $\frac{2}{n(n-1)} $.
