# align*

Displayed multi-line derivations and systems with alignment points, but without automatic equation numbers.

https://texform.dev/latex/environments/align-star

## Metadata

| Field | Value |
| --- | --- |
| Topic | [Alignment](https://texform.dev/latex/topics/alignment) |
| Packages | ams |
| Allowed mode | math |
| Tags | math-alignment |
| Commonality | high |
| Body mode | math |

## Syntax

### ams

Argument specification: ``

Displayed multi-line derivations and systems with alignment points, but without automatic equation numbers.

## Common tasks

### How to align equations without numbers

```latex
\begin{align*} a &= b+c \\ &= d \end{align*}
```

[Open in Playground](https://play.texform.dev/?input=%5Cbegin%7Balign*%7D+a+%26%3D+b%2Bc+%5C%5C+%26%3D+d+%5Cend%7Balign*%7D)

### How to write an unnumbered system

```latex
\begin{align*} x+y &= 1 \\ x-y &= 0 \end{align*}
```

[Open in Playground](https://play.texform.dev/?input=%5Cbegin%7Balign*%7D+x%2By+%26%3D+1+%5C%5C+x-y+%26%3D+0+%5Cend%7Balign*%7D)

### How to suppress numbering on a derivation

align* is the unnumbered sibling of align; \nonumber also works inside align.

```latex
\begin{align*} f'(x) &= \lim_{h\to 0}\frac{f(x+h)-f(x)}{h} \\ &= 2x \end{align*}
```

[Open in Playground](https://play.texform.dev/?input=%5Cbegin%7Balign*%7D+f%27%28x%29+%26%3D+%5Clim_%7Bh%5Cto+0%7D%5Cfrac%7Bf%28x%2Bh%29-f%28x%29%7D%7Bh%7D+%5C%5C+%26%3D+2x+%5Cend%7Balign*%7D)

## Examples

```latex
\begin{align*} a &= b \end{align*}
```

[Open in Playground](https://play.texform.dev/?input=%5Cbegin%7Balign*%7D+a+%26%3D+b+%5Cend%7Balign*%7D)

## Renderer support

| Package | MathJax | KaTeX | XeTeX |
| --- | --- | --- | --- |
| ams | full | none | full |

## Usage frequency

6.82% of formulas in the measured corpus contain this entry, rank 4 of 31 entries with frequency data.

## In TeXForm

TeXForm reads the environment body in math mode.

## See also

- [align](https://texform.dev/latex/environments/align)
- [eqnarray](https://texform.dev/latex/environments/eqnarray)
- [eqnarray*](https://texform.dev/latex/environments/eqnarray-star)
- [gather](https://texform.dev/latex/environments/gather)
- [gather*](https://texform.dev/latex/environments/gather-star)
- [split](https://texform.dev/latex/environments/split)

## Test cases

### ams

| Input | Case | MathJax | KaTeX | XeTeX |
| --- | --- | --- | --- | --- |
| \begin{align*} a & b \end{align*} | Positive: baseline | Pass | Fail | Pass |