| \(\displaystyle f(x) = \sum_{n=0}^{\infty} c_n x^n \) |
Interval of Convergence | Radius of Convergence |
|---|---|---|
| \(\displaystyle \frac{1}{1-x} = \sum_{n=0}^{\infty} x^n = 1+ x + x^2 + x^3 + \cdots \) | \((-1,1)\) | 1 |
| \(\displaystyle e^x = \sum_{n=0}^{\infty} \frac{x^n}{n!} = 1+ x + \frac{x^2}{2!} + \frac{x^3}{3!} + \cdots \) | \((-\infty,\infty)\) | \( \infty \) |
| \(\displaystyle \begin{aligned} \sin x & = \sum_{n=0}^{\infty} (-1)^n\frac{x^{2n+1}}{(2n+1)!} \\ & = x – \frac{x^3}{3!} + \frac{x^5}{5!} – \frac{x^7}{7!} + \cdots \end{aligned} \) | \((-\infty,\infty)\) | \(\infty\) |
|
\(\displaystyle \begin{aligned} \cos x & = \sum_{n=0}^{\infty} (-1)^n\frac{x^{2n}}{(2n)!} \\ & = 1 – \frac{x^2}{2!} + \frac{x^4}{4!} – \frac{x^6}{6!} + \cdots \end{aligned} \) |
\((-\infty,\infty)\) | \(\infty\) |
|
\(\displaystyle \begin{aligned} \tan^{-1} x & = \sum_{n=0}^{\infty} (-1)^n\frac{x^{2n+1}}{2n+1} \\ & = x – \frac{x^3}{3} + \frac{x^5}{5} – \frac{x^7}{7} + \cdots \end{aligned} \) |
\((-1,1]\) | \(1\) |
|
\(\displaystyle \begin{aligned} \ln(1+ x) & = \sum_{n=1}^{\infty} (-1)^{n-1}\frac{x^n}{n} \\ & = x – \frac{x^2}{2} + \frac{x^3}{3} – \frac{x^4}{4} + \cdots \end{aligned} \) |
\((-1,1]\) | \(1\) |
|
\(\displaystyle \begin{aligned} (1+ x)^k &= \sum_{n=0}^{\infty} {k \choose n} x^n \\ &= 1 + k x + \frac{k(k-1)}{2!}x^2 + \cdots \end{aligned}\) |
\( \scriptstyle \begin{cases} [-1,1], & \text{ if } k > -1 \text{ & } k \not \in \mathbb{Z} \\ (-\infty, \infty), & \text{ if } k>-1 \text{ & } k \in \mathbb{Z} \\ (-1,1], & \text{ if } k=-1\\ \end{cases}\) |
\(1\) |
| \(\displaystyle f(x) = \sum_{n=0}^{\infty} c_n x^n \) |
Interval of Convergence | Radius of Convergence |
|---|---|---|
| \(\displaystyle \frac{1}{1-x} = \sum_{n=0}^{\infty} x^n \) | \((-1,1)\) | 1 |
| \(\displaystyle e^x = \sum_{n=0}^{\infty} \frac{x^n}{n!}\) | \((-\infty,\infty)\) | \( \infty \) |
| \(\displaystyle \sin x = \sum_{n=0}^{\infty} (-1)^n\frac{x^{2n+1}}{(2n+1)!} \) | \((-\infty,\infty)\) | \(\infty\) |
|
\(\displaystyle \cos x = \sum_{n=0}^{\infty} (-1)^n\frac{x^{2n}}{(2n)!} \) |
\((-\infty,\infty)\) | \(\infty\) |
|
\(\displaystyle \tan^{-1} x = \sum_{n=0}^{\infty} (-1)^n\frac{x^{2n+1}}{2n+1} \) |
\((-1,1]\) | \(1\) |
|
\(\displaystyle \ln(1+ x) = \sum_{n=1}^{\infty} (-1)^{n-1}\frac{x^n}{n} \) |
\((-1,1]\) | \(1\) |
|
\( (1+ x)^k = \sum_{n=0}^{\infty} {k \choose n} x^n \) |
\(\scriptstyle \begin{cases} [-1,1], \; & \text{ if } k > -1 \text{ & } k \not \in \mathbb{Z} \\ (-\infty, \infty), \; & \text{ if } k>-1 \text{ & } k \in \mathbb{Z} \\ (-1,1], \; & \text{ if } k=-1\\ \end{cases}\) |
\(1\) |
-
\(\displaystyle \frac{1}{1-x} = \sum_{n=0}^{\infty} x^n\)
- Interval of Convergence: \((-1,1)\)
- Radius of Convergence: 1
-
\(\displaystyle e^x = \sum_{n=0}^{\infty} \frac{x^n}{n!} \)
- Interval of Convergence: \((-\infty,\infty)\)
- Radius of Convergence: \( \infty \)
-
\(\displaystyle \sin x = \sum_{n=0}^{\infty} (-1)^n\frac{x^{2n+1}}{(2n+1)!} \)
- Interval of Convergence: \((-\infty,\infty)\)
- Radius of Convergence: \(\infty\)
-
\(\displaystyle
\cos x = \sum_{n=0}^{\infty} (-1)^n\frac{x^{2n}}{(2n)!}
\)- Interval of Convergence: \((-\infty,\infty)\)
- Radius of Convergence: \(\infty\)
-
\(\displaystyle
\tan^{-1} x = \sum_{n=0}^{\infty} (-1)^n\frac{x^{2n+1}}{2n+1}
\)- Interval of Convergence: \((-1,1]\)
- Radius of Convergence: \(1\)
-
\(\displaystyle
\ln(1+ x) = \sum_{n=1}^{\infty} (-1)^{n-1}\frac{x^n}{n}
\)- Interval of Convergence: \((-1,1]\)
- Radius of Convergence: \(1\)
-
\(\displaystyle
(1+ x)^k = \sum_{n=0}^{\infty} {k \choose n} x^n \)- Interval of Convergence:
$$ \begin{cases}
[-1,1], & k > -1 \text{ & } k \not \in \mathbb{Z} \\
(-\infty, \infty), & k>-1 \text{ & } k \in \mathbb{Z} \\
(-1,1], & k=-1\\
\end{cases}
$$ - Radius of Convergence: \(1\)
- Interval of Convergence: