JAVASCRIPT

$ is not defined

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js" type="text/javascript"></script>

Uncaught ReferenceError: $ is not defined

<script src="https://code.jquery.com/jquery-1.9.1.js"></script>
<script src="path-para-seu-script"></script>

Uncaught ReferenceError: $ is not defined

jQuery must be loaded first before your script. 

example:
<script src="path/to/jquery.js"></script> <!-- or using CDN is up to you  -->
<script type="text/javascript">
	// your script here...
</script>

Uncaught ReferenceError: $ is not defined

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js" type="text/javascript"></script>

Uncaught ReferenceError: $ is not defined

You should put the references to the jquery scripts first.
<script src="jquery-3.5.1.js"></script>
<script type="text/javascript" src="script.js"></script>

Uncaught ReferenceError: $ is not defined

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>

Uncaught ReferenceError: $ is not defined

<script src="http://code.jquery.com/jquery-1.10.2.js"></script>
<script src="http://code.jquery.com/ui/1.11.2/jquery-ui.js"></script>
<script src="http://maxcdn.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js"></script>
<script src="exponential.js"></script>

$ is not defined

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js" type="text/javascript"></script>

$ is not defined

put <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.0/jquery.min.js"></script> 
before <script src="script.js"></script>

$ not defined error

<script src="http://ajax.googleapis.com/ajax/libs/jquery/2.0.0/jquery.min.js"></script>
<script type="text/javascript" src="./javascript.js"></script>
<script
    src="http://maps.googleapis.com/maps/api/js?key=YOUR_APIKEY&sensor=false">
</script>

Uncaught ReferenceError: $ is not defined

make sure that your jquery script is being loaded before every other script