equationsmath-modemath-operators
In LaTeX, I want to create the following equation:
\begin{equation}
x(t) = A1 sin(2 \pi f_1 t) + A2 sin(2 \pi f_2 t)
\end{equation}
I don't want to show the multiplication sign. But is there a way to have a space where the multiplication sign would be? So for example between A1 and sin() ?
Also, how can I change the letter size of my equation?
Thanks for help!
Here is a small sample of numbering equations.
\documentclass[12pt]{article}
\usepackage{amsmath}
\begin{document}
\begin{align} % numbers equations automatically
x &= (1-x) + 2x \\ % \\ ends the line
&= (x+y) - y \nonumber \\ % \nonumber removes the equation number
&= \frac{x}{2} + \frac{x}{2} % last line does not have \\
\end{align}
\begin{align*} % use of * removes all numbers in this block
x &= (2x + 5) - (x+5) \\
&= yx - (y-1) x
\end{align*}
\end{document}
This sample produces
You can either reduce the value \arraycolsep and use the fleqn environment from nccmath, or use the medsize environment, also from nccmath, which reduces the font size to about 80 % of \displaystyle.
\documentclass{ieeetran}
\usepackage{amsmath, nccmath}
\usepackage{lipsum}
\begin{document}
\lipsum[1]
\begin{fleqn}
\begin{equation}
\setlength{\arraycolsep}{3pt}
\begin{bmatrix}
-k_w + \sin α₁ & -k_w +1 & -k_w + \sin α₁ \\
\sin 5α₁ & 1 & \sin 5α₁ \\
\sin 7α₁ & -11 & \sin7α₁ \\
\end{bmatrix}
\!
\begin{bmatrix}
N₁ \\ N₂ \\ N₃
\end{bmatrix}
=
\begin{bmatrix}
0 \\ 0 \\ 0
\end{bmatrix}
\end{equation}
\end{fleqn}
\lipsum[3]
\begin{equation}
\begin{medsize}
\begin{bmatrix}
-k_w + \sin α₁ & -k_w +1 & -k_w + \sin α₁ \\
\sin 5α₁ & 1 & \sin 5α₁ \\
\sin 7α₁ & -11 & \sin7α₁ \\
\end{bmatrix}
\!
\begin{bmatrix}
N₁ \\ N₂ \\ N₃
\end{bmatrix}
=
\begin{bmatrix}
0 \\ 0 \\ 0
\end{bmatrix}
\end{medsize}
\end{equation}
\lipsum[3]
\end{document}
Best Answer
As Au101 pointed out, use
\sin. Also, you presumably want a subscript on the A's.