Suites et Séries

Sommes

\[ k \ge 1 \quad a_0 \in \mathbb{R} \] \[ S(n) = \]
formule
récursive
formule
directe
\[ \sum_{k=i}^{n} (a_k) \] \[ \sum_{k=i}^{\infin} (a_k) \]
arithmétique \[ a_k = a_{k - 1} + r \] \[ a_k = a_0 + r \cdot k \] \[ \begin{aligned} nbt \cdot \frac{p + d}{2} \end{aligned} \]
géométrique \[ a_k = a_{k - 1} \cdot r \] \[ a_k = a_0 \cdot r^k \\[1em] \] \[ \frac{p - d \cdot r}{1 - r} \\[1em] \] \[ \frac{a_0}{1 - r} \]

Quelques

\[ \begin{aligned} & \sum_{k=1}^{} = 1,~ 3,~ 6,~ 10,~ 15, ... \\ & \prod_{k=1}^{} = 1,~ 2,~ 6,~ 24,~ 120, ... \end{aligned} \]

Égalités

\[ \bigoplus \] \[ \sum \] \[ \prod \]
\[ \bigoplus_{k=1}^n (c) \] \[ n c \] \[ c^n \]
\[ \bigoplus_{k=1}^n (k) \] \[ \frac{n (n + 1)}{2} \] \[ n! \]
\[ \bigoplus_{k=1}^n (a_k \cdot c) \] \[ c \cdot \sum_{k=1}^n (a_k) \] \[ c^n \cdot \prod_{k=1}^n (a_k) \]
\[ \bigoplus_{k=i}^n \bigoplus_{l=j}^m (a_k \cdot b_l) = \bigoplus_{k=i}^n (a_k) \cdot \bigoplus_{l=j}^m (b_l) \\[1em] \]
\[ \begin{aligned} \bigoplus_{k=i}^n (a_k \oplus b_k) \quad = \quad \bigoplus_{k=i}^n (a_k) ~ \oplus ~ \bigoplus_{k=i}^n (b_k) \end{aligned} \]
\[ \begin{aligned} \orange{\bigoplus_{k=i}^n} \blue{\bigotimes_{l=j}^m} (a_{\orange{i} \blue{j}}) \quad = \quad \blue{\bigotimes_{l=j}^m} \orange{\bigoplus_{k=i}^n} (a_{\orange{i} \blue{j}}) \end{aligned} \]
\[ \begin{aligned} & \bigoplus_{i = 1}^n \bigoplus_{\orange{j = i}}^n (a_{ij}) \quad = \quad \bigoplus_{j = 1}^n \bigoplus_{i = 1}^\orange{j} (a_{ij}) \end{aligned} \]

Parallèles ou autres notations non conventionnelles

\[ \begin{aligned} & \sum_{i \in I}^n \sum_{j = F(i)}^n (a_{ij}) \end{aligned} \]
\[ \begin{aligned} & f : && \mathbb{N} && \rightarrow && \mathbb{R} \\[1em] & && i && \mapsto && a_i \end{aligned} \]