I am using amsmath
package but keep getting errors with the following:
\begin{split}
\[
A_R&=\frac{4}{9}+\frac{20}{81}+\frac{100}{729}+\frac{500}{6561}+\dots \\
&=\frac{4}{3^2}+5\times\frac{4}{3^4}+5\times5\times\frac{4}{3^6}+5\times5\times5\times\frac{4}{3^8}+\dots \\
&=\sum_{n=1}^{\infty}5^{n-1}\times\frac{4}{3^{2n}} \\
&=\sum_{n=0}^{\infty}5^{n-1}\times\frac{4}{3^2n+2}} \\
&=\frac{\frac{4}{9}}{1-\frac{5}{9}} \\
&=1
\]
\end{split}
The error is detected on the line after \end{split}
and I cannot understand why.
I also get:
! Argument of \split has an extra }.
! Extra }, or forgotten \endgroup.
\[ \begin{split} A_R&=\frac{4}{9}+\frac{20}{81}+\frac{100}{729}+\frac{500}{6561}+\dots \\ &=\frac{4}{3^2}+5\times\frac{4}{3^4}+5\times5\times\frac{4}{3^6}+5\times5\times5\times\frac{4}{3^8}+\dots \\ &=\sum_{n=1}^{\infty}5^{n-1}\times\frac{4}{3^{2n}} \\ &=\sum_{n=0}^{\infty}5^{n-1}\times\frac{4}{3^2n+2} \\ &=\frac{\frac{4}{9}}{1-\frac{5}{9}} \\ &=1 \end{split} \]
align*
instead?