\[ \begin{split}
&( \frac{21! \cdot 2^3}{3! 18! \cdot 4^{18}} +
\frac{21! \cdot 2^2}{2! 2! 17! \cdot 5^2 \cdot 4^{17}} \\
& + \frac{21! \cdot 2}{4! 16! \cdot 5^4 \cdot 4^{16}} +
frac{21!}{6! 15! \cdot 5^6 \cdot 4^{15}} ) x^{36} \\
&= ( \frac{38138681}{67108864000000} ) x^{36}
\end{split} \]
有什么问题吗？日志没有告诉我任何有用的信息。以下是完整文件：
\documentclass[letterpaper, 12pt, titlepage]{article}
\pagestyle{myheadings} \markright{Fakaff \hfill MATH2P81 \hfill}
\usepackage{amsmath}
\begin{document}
\title{MATH 2P81 \\ Assignment \#1}
\date{\today}
\author{Fakaff \\ \texttt{4847653}}
\maketitle
\begin{enumerate}
\item All terms of the expansion will be of the form $ \binom{21}{a, b, c} 2^a x^b (x^2)^c $. To
find the coefficient of $ x^{36} $, we must first find all sets $ \{a, b, c\} $ such that
$ a + b + c = 21 $ and $ a + b + 2c = 36 $:
$\{3, 0, 18\} $
$ \{2, 2, 17\} $
$ \{1, 4, 16 \} $
$ \{0, 6, 15 \} $
Plugging these numbers into our formula, we get:
\[ \begin{split}
&( \frac{21! \cdot 2^3}{3! 18! \cdot 4^{18}} + \frac{21! \cdot 2^2}{2! 2! 17! \cdot 5^2 \cdot 4^{17}} \\
& + \frac{21! \cdot 2}{4! 16! \cdot 5^4 \cdot 4^{16}} + frac{21!}{6! 15! \cdot 5^6 \cdot 4^{15}} ) x^{36} \\
&= ( \frac{38138681}{67108864000000} ) x^{36}
\end{split} \]
Checking in maple by using the \texttt{expand( (2 - (x/5) + (x^2/4 )^21 )} command confirms this result.
\end{enumerate}
\end{document}
答案1
您缺少$以下单词的 s：
Checking in maple by using the \texttt{expand$(2 - (x/5) + (x^2/4 )^21)$} command confirms this result.
并且您还缺少\a 中的a \frac。完整的更正版本如下（我还添加了\left(,\right)括号，因为它们将根据封闭文本的垂直高度调整大小。left.和\right.是必需的，因为我们需要\left在同一行上与“left”匹配。
\documentclass[letterpaper, 12pt, titlepage]{article}
\pagestyle{myheadings} \markright{Fakaff \hfill MATH2P81 \hfill}
\usepackage{amsmath}
\begin{document}
\title{MATH 2P81 \\ Assignment \#1}
\date{\today}
\author{Fakaff \\ \texttt{4847653}}
\maketitle
\begin{enumerate}
\item All terms of the expansion will be of the form $ \binom{21}{a, b, c} 2^a x^b (x^2)^c $. To
find the coefficient of $ x^{36} $, we must first find all sets $ \{a, b, c\} $ such that
$ a + b + c = 21 $ and $ a + b + 2c = 36 $:
$\{3, 0, 18\} $
$ \{2, 2, 17\} $
$ \{1, 4, 16 \} $
$ \{0, 6, 15 \} $
Plugging these numbers into our formula, we get:
\[ \begin{split}
&\left( \frac{21! \cdot 2^3}{3! 18! \cdot 4^{18}} + \frac{21! \cdot 2^2}{2! 2! 17! \cdot 5^2 \cdot 4^{17}} \right.\\
& \left. + \frac{21! \cdot 2}{4! 16! \cdot 5^4 \cdot 4^{16}} + \frac{21!}{6! 15! \cdot 5^6 \cdot 4^{15}} \right) x^{36} \\
&= \left( \frac{38138681}{67108864000000} \right) x^{36}
\end{split} \]
Checking in maple by using the \texttt{expand$(2 - (x/5) + (x^2/4 )^21)$} command confirms this result.
\end{enumerate}
\end{document}
如果您不想格式化内的文本\expand，而是想要符号^，则可以使用：
Checking in maple by using the \texttt{expand(2 - (x/5) + (x\textasciicircum 2/4 )\textasciicircum 21)} command confirms this result.
答案2
问题是里面的文本\texttt{}包含数学符号，因此您需要$字符，正如所指出的那样@Peter Grill。
或者，你可以将有问题的行替换为：
Checking in maple by using the $\mathtt{expand( (2 - (x/5) + (x^2/4 )^21 )}$ command confirms this result.
结果整个表达式被排版成“打字机”字体，我想这正是你想要的。