Combination Theorem for Sequences/Multiple Rule

Theorem

Real Sequences

Let $\sequence {x_n}$ be a sequences in $\R$.

Let $\sequence {x_n}$ be convergent to the following limit:

$\ds \lim_{n \mathop \to \infty} x_n = l$


Let $\lambda \in \R$.


Then:

$\ds \lim_{n \mathop \to \infty} \paren {\lambda x_n} = \lambda l$


Complex Sequences

Let $\sequence {z_n}$ be a sequence in $\C$.

Let $\sequence {z_n}$ be convergent to the following limit:

$\ds \lim_{n \mathop \to \infty} z_n = c$


Let $\lambda \in \C$.


Then:

$\ds \lim_{n \mathop \to \infty} \paren {\lambda z_n} = \lambda c$


Also see


Sources

  • 1998: David Nelson: The Penguin Dictionary of Mathematics (2nd ed.) ... (previous) ... (next): convergent series
  • 2008: David Nelson: The Penguin Dictionary of Mathematics (4th ed.) ... (previous) ... (next): convergent series