Question: I have four different divs with slideToggle function. I set them to slidetoggle on click, and they work fine. However, I want the rest of the divs to close when one div is clicked. can anyone help?
below is the code I have so far. 

```
<div id="01"><p>title</p></div>
    <div id="01_sub"><p>content</p></div>
<div id="02"><p>title</p></div>
    <div id="02_sub"><p>content</p></div>
<div id="03"><p>title</p></div>
    <div id="03_sub"><p>content</p></div>
<div id="04"><p>title</p></div>
    <div id="04_sub"><p>content</p></div>

$('#01_sub').hide();
      $('#01').click(function() {
       $('#01_sub').slideToggle('medium');
     });
     $('#02_sub').hide();
      $('#02').click(function() {
       $('#02_sub').slideToggle('medium');
     });
     $('#03_sub').hide();
      $('#03').click(function() {
       $('#03_sub').slideToggle('medium');
     });
     $('#04_sub').hide();
      $('#04').click(function() {
       $('#04_sub').slideToggle('medium');
     });

```

so basically, if I click #01, I want #02,#03,#04 to stay closed or to be closed. and if I click #02, I want the rest to close.

Answer: 
```
#define f(x) 1/(1+x*x)

```

should be defined as

```
#define f(x) 1/(1+(x)*(x))

```
Try this:

```
#define f(x) (1/(1+x*x))

```

A `#define` basically sticks the code where the `#define`'d name was, so order of operations and precedence will apply.