<parameter>max</parameter>, whichever has more.
       </para>
       <para>
        <literal>random(1, 10)</literal>
        <returnvalue>7</returnvalue>
       </para>
       <para>
        <literal>random(-0.499, 0.499)</literal>
        <returnvalue>0.347</returnvalue>
       </para></entry>
      </row>

      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <indexterm>
         <primary>random_normal</primary>
        </indexterm>

         <function>random_normal</function> (
         <optional> <parameter>mean</parameter> <type>double precision</type>
         <optional>, <parameter>stddev</parameter> <type>double precision</type> </optional></optional> )
         <returnvalue>double precision</returnvalue>
       </para>
       <para>
        Returns a random value from the normal distribution with the given
        parameters; <parameter>mean</parameter> defaults to 0.0
        and <parameter>stddev</parameter> defaults to 1.0
       </para>
       <para>
        <literal>random_normal(0.0, 1.0)</literal>
        <returnvalue>0.051285419</returnvalue>
       </para></entry>
      </row>

      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <indexterm>
         <primary>setseed</primary>
        </indexterm>
        <function>setseed</function> ( <type>double precision</type> )
        <returnvalue>void</returnvalue>
       </para>
       <para>
        Sets the seed for subsequent <literal>random()</literal> and
        <literal>random_normal()</literal> calls;
        argument must be between -1.0 and 1.0, inclusive
       </para>
       <para>
        <literal>setseed(0.12345)</literal>
       </para></entry>
      </row>
     </tbody>
    </tgroup>
   </table>

  <para>
   The <function>random()</function> and <function>random_normal()</function>
   functions listed in <xref linkend="functions-math-random-table"/> use a
   deterministic pseudo-random number generator.
   It is fast but not suitable for cryptographic
   applications; see the <xref linkend="pgcrypto"/> module for a more
   secure alternative.
   If <function>setseed()</function> is called, the series of results of
   subsequent calls to these functions in the current session
   can be repeated by re-issuing <function>setseed()</function> with the same
   argument.
   Without any prior <function>setseed()</function> call in the same
   session, the first call to any of these functions obtains a seed
   from a platform-dependent source of random bits.
  </para>

  <para>
   <xref linkend="functions-math-trig-table"/> shows the
   available trigonometric functions.  Each of these functions comes in
   two variants, one that measures angles in radians and one that
   measures angles in degrees.
  </para>

   <table id="functions-math-trig-table">
    <title>Trigonometric Functions</title>

    <tgroup cols="1">
     <thead>
      <row>
       <entry role="func_table_entry"><para role="func_signature">
        Function
       </para>
       <para>
        Description
       </para>
       <para>
        Example(s)
       </para></entry>
      </row>
     </thead>

     <tbody>
      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <indexterm>
         <primary>acos</primary>
        </indexterm>
        <function>acos</function> ( <type>double precision</type> )
        <returnvalue>double precision</returnvalue>
       </para>
       <para>
        Inverse cosine, result in radians
       </para>
       <para>
        <literal>acos(1)</literal>
        <returnvalue>0</returnvalue>
       </para></entry>
      </row>

      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <indexterm>
         <primary>acosd</primary>
        </indexterm>
        <function>acosd</function> ( <type>double precision</type> )
        <returnvalue>double precision</returnvalue>
       </para>
       <para>
        Inverse cosine, result in degrees