\(\huge f(x) = \frac{1}{1+x}\)
\(\huge \frac{1}{1+x}=\sum_0^\infty (-x)^n=1-x+x^2-x^3+x^4...\)\(\huge f(x) = e^{x}\)
\(\huge e^{x}=\sum_0^\infty \frac{x^{n}}{n!}=1+x+\frac{x^2}{2}+\frac{x^3}{6}+\frac{x^4}{24}+\frac{x^5}{120}...\)\(\huge ln(1+x)\)
\(\huge \sum_1^\infty ln(1+x)=\frac{(-1)^{n+1}}{n}*x^{n}=x-\frac{x^2}{2}+\frac{x^3}{3}-\frac{x^4}{4}+\frac{x^5}{5}-\frac{x^6}{6}...\) (-1, 1]