feat: add tip to disable mathjax processing for an element

en_us/shared/exercises_tools/text_input.rst

@@ -113,8 +113,8 @@ Editing Text Input Problems using the Advanced Editor
 *********************************************************************
 
 If the simple editor is not enough to meet your needs, you can switch over to the
-advanced editor. In the setting panels on the right of the editor, click 
-**Show advanced settings**, then scroll down and click 
+advanced editor. In the setting panels on the right of the editor, click
+**Show advanced settings**, then scroll down and click
 **Switch to advanced editor**.
 
 You can use the advanced editor to identify the elements of a text input problem
@@ -342,6 +342,29 @@ Patterns", "string patterned", or "STRING PATTERNING" are all scored as
 correct, but learners who submit an answer of "Strings Pattern" or "string
 patern" are scored as incorrect.
 
+=========================
+Disable MathJax rendering
+=========================
+
+You can configure a text input problem to accept raw expressions which could
+resemble functions that are processed by MathJax by default. Sometimes this
+might not be the expected behaviour, i.e., you want to accept raw expression as
+well as display (show answer) it in its raw form. You can do this by simply
+enclosing ``<stringresponse>`` element in ``<annotation-xm>`` tag. All elements
+inside this tag will be ignored by MathJax processor. An example follows.
+
+.. code-block:: xml
+
+   <problem>
+     <annotation-xml>
+       <stringresponse class="tex2jax_ignore" answer="\s*n\s**?\s*x\[\s*n\s*\]\s*" type="ci">
+         <div>Question</div>
+         <additional_answer class="tex2jax_ignore" answer="or \s*x\[\s*n\s*\]\s**?\s*n\s*"></additional_answer>
+         <textline size="20"></textline>
+       </stringresponse>
+     </annotation-xml>
+   </problem>
+
 .. _Text Input Problem XML:
 
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