f ( x ) {\displaystyle f(x)\,\!} = ∑ n = 0 ∞ a n x n {\displaystyle =\sum _{n=0}^{\infty }a_{n}x^{n}} = a 0 + a 1 x + a 2 x 2 + ⋯ {\displaystyle =a_{0}+a_{1}x+a_{2}x^{2}+\cdots } √ , 2 , 2 n , x 3 + y 3 2 3 {\displaystyle \surd ,{\sqrt {2}},{\sqrt[{n}]{2}},{\sqrt[{3}]{\frac {x^{3}+y^{3}}{2}}}}
![{\displaystyle \surd ,{\sqrt {2}},{\sqrt[{n}]{2}},{\sqrt[{3}]{\frac {x^{3}+y^{3}}{2}}}}](https://en.wikipedia.org/api/rest_v1/media/math/render/svg/fb2f06b0dec0a42806cf1378d9e9b64f10574c1d)
