# spacing in equations

I need to make this formula

This is what I have so far:

\Delta(x)=\left\{
\begin{array}{ll}
1  \mathrm{if} x>0\\
-1 \mathrm{if} x<0 (1)\\
0 \mathrm{otherwise}
\end{array}
\right.


Which it is correct just not sure how to space it properly.

The formula attached in the image is not typeset right. It uses array, which is not the right tool in this case. amsmath offers you cases which is exactly for this purpose.
\documentclass{article}
$$\Delta(x)=\begin{cases} 1 & \text{if x>0}\\ -1 & \text{if x<0}\\ 0 & \text{otherwise} \end{cases}$$