# Align equation with a better method than {split}?

I've got the following code that I'm using and wondered if there was a way to get the minus sign (-) of the third term to align with the minus sign of the second term, or if there was a nicer way to set it out in general while keeping to the two column layout?

Also, is it possible to make the brackets outside the third term slightly larger?

\documentclass[11pt]{article}
\usepackage{amsmath}
\usepackage{a4wide}
\usepackage{multicol}

\begin{document}
\begin{multicols*}{2}
$$\begin{split} \frac{d^2x}{d\theta^2}=-r\cos(\theta) - \frac{r^2(\cos^2(\theta) -\sin^2 (\theta))}{\sqrt{l^2-r^2\sin^2(\theta)}} \\-\frac{r^4\sin^2(\theta) \cos^2 (\theta)}{(\sqrt{l^2-r^2\sin^2 \theta})^3} \end{split}$$
\end{multicols*}{2}
\end{document}

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You can use \left( and right) to make the brackets larger. Any reason why you don't want to use align? – Peter Grill Feb 13 '12 at 1:32
The align environment is intended for aligning separate equations and will print two equation numbers. But split allows alignment, as Dr. Kumar points out. – Nathan Grigg Feb 13 '12 at 2:24
You can use the \nonumber command to suppress assignment of equation numbers. – cm2 Feb 13 '12 at 3:20
Notice that the a4wide package is considered obsolete and should not be used. – egreg Feb 13 '12 at 8:50
A minor point: You should be consistent in how you specify the angle. In most cases you have (\theta), but you also use it without the (). In this particular case I would just remove the () as the meaning is obvious, but that is a personal preference. – Peter Grill Feb 13 '12 at 18:45

You should use & at proper places.

\documentclass[11pt]{article}
\usepackage{amsmath}
%
\begin{document}
$$\begin{split} \frac{d^2x}{d\theta^2}=-r\cos(\theta) & % one & here <================ - \frac{r^2(\cos^2(\theta) -\sin^2 (\theta))}{\sqrt{l^2-r^2\sin^2(\theta)}}\\ & % another & here <============= -\frac{r^4\sin^2(\theta) \cos^2 (\theta)}{\left(\sqrt{l^2-r^2\sin^2 \theta}\right)^3} \end{split}$$
\end{document}


Then you will get the desired alignment. Also I have made the parenthesis around the third term bigger.

You can find the delimiters in amsldoc.pdf (ams documentation) bottom of page number 15. I have attached a screen shot for you.

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Thank you, that's much better. Have you any idea about the bracket sizing? – Andy Feb 13 '12 at 3:04
As Peter pointed out in a comment to your question, use \left( and \right) to allow for dynamic sizing of parenthesis, or whatever other symbol you want. – cm2 Feb 13 '12 at 3:21
@Andy I edited my answer to include delimiters – Harish Kumar Feb 13 '12 at 4:21
Thanks for the help, it looks great. – Andy Feb 13 '12 at 13:58
@Andy, If you think that the answer has solved your problem, it's helpful to click on the green check mark next to it to "accept" the answer. This helps others who may encounter the same problem to find answers that work. – Harish Kumar Feb 13 '12 at 22:44