Create a command \summation{n}{\alpha}

Question

How do I solve this type of question? I don't understand what im suppose to do. What does it mean "show two uses with different arguments?"

Answer 1

I don't understand what I'm supposed to do.

I'm virtually certain that you are supposed to

• create a TeX or LaTeX command -- a "macro" in TeX jargon -- called \summation which takes two arguments, and

• show two uses of this macro, say, \summation{n}{\alpha} and \summation{m}{\omega}.

Presumably, you are also supposed to create a sample PlainTeX or LaTeX document which (a) features the macro definition and the two uses of \summation and (b) compiles without crashing.

First, a PlainTeX-based solution:

\def\summation#1#2{\sum_{i=0}^{#1}#2_i} % use in math mode only
$\summation{n}{\alpha}$, $\summation{m}{\omega}$
\bye

Second, a LaTeX-based solution:

\documentclass{article}
\newcommand\summation[2]{\sum_{i=0}^{#1}#2_i} % use in math mode only
\begin{document}
$\summation{n}{\alpha}$, $\summation{m}{\omega}$
\end{document}

Answer 2

You can create this command by adding the following line in the preamble of your latex document:

\newcommand{\summation}[2]{$\sum\limits_{i=0}^{#1} #2 _i$}

And the question asks to use this command within text for different arguments. For example, you can add this code to the main latex file:

This is an example when we type \verb|\summation{n}{\alpha}| 
within text yields \summation{n}{\alpha} and if we change parameters 
as \verb|\summation{k}{\beta}| we get \summation{k}{\beta} after compilation.

after compiling you will get:

It is just to show that you have created a new command and you use it in your document in two different cases.