- #1
epimorphic
- 3
- 0
I have a rather silly limit question.
Consider
\begin{equation}
\lim_{x \rightarrow \infty} f(x)
\end{equation}
and assume it exists. Suppose now that
\begin{equation}
x = a\, t + b\, g(t),
\end{equation}
where [itex] a [/itex] and [itex] b [/itex] are constants and [itex] g(t) [/itex] is a periodic function of [itex] t [/itex]. Now, is it correct to simply replace [itex] \lim_{x \rightarrow \infty} [/itex] by [itex] \lim_{t \rightarrow \infty} [/itex] as [itex] x \rightarrow \infty [/itex] if and only if [itex] t \rightarrow \infty [/itex]? That is, is it correct to write
\begin{equation}
\lim_{x \rightarrow \infty} f(x) = \lim_{t \rightarrow \infty} f(x(t))\;?
\end{equation}
Consider
\begin{equation}
\lim_{x \rightarrow \infty} f(x)
\end{equation}
and assume it exists. Suppose now that
\begin{equation}
x = a\, t + b\, g(t),
\end{equation}
where [itex] a [/itex] and [itex] b [/itex] are constants and [itex] g(t) [/itex] is a periodic function of [itex] t [/itex]. Now, is it correct to simply replace [itex] \lim_{x \rightarrow \infty} [/itex] by [itex] \lim_{t \rightarrow \infty} [/itex] as [itex] x \rightarrow \infty [/itex] if and only if [itex] t \rightarrow \infty [/itex]? That is, is it correct to write
\begin{equation}
\lim_{x \rightarrow \infty} f(x) = \lim_{t \rightarrow \infty} f(x(t))\;?
\end{equation}