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
       </para>
       <para>
        <literal>acosd(0.5)</literal>
        <returnvalue>60</returnvalue>
       </para></entry>
      </row>

      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <indexterm>
         <primary>asin</primary>
        </indexterm>
        <function>asin</function> ( <type>double precision</type> )
        <returnvalue>double precision</returnvalue>
       </para>
       <para>
        Inverse sine, result in radians
       </para>
       <para>
        <literal>asin(1)</literal>
        <returnvalue>1.5707963267948966</returnvalue>
       </para></entry>
      </row>

      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <indexterm>
         <primary>asind</primary>
        </indexterm>
        <function>asind</function> ( <type>double precision</type> )
        <returnvalue>double precision</returnvalue>
       </para>
       <para>
        Inverse sine, result in degrees
       </para>
       <para>
        <literal>asind(0.5)</literal>
        <returnvalue>30</returnvalue>
       </para></entry>
      </row>

      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <indexterm>
         <primary>atan</primary>
        </indexterm>
        <function>atan</function> ( <type>double precision</type> )
        <returnvalue>double precision</returnvalue>
       </para>
       <para>
        Inverse tangent, result in radians
       </para>
       <para>
        <literal>atan(1)</literal>
        <returnvalue>0.7853981633974483</returnvalue>
       </para></entry>
      </row>

      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <indexterm>
         <primary>atand</primary>
        </indexterm>
        <function>atand</function> ( <type>double precision</type> )
        <returnvalue>double precision</returnvalue>
       </para>
       <para>
        Inverse tangent, result in degrees
       </para>
       <para>
        <literal>atand(1)</literal>
        <returnvalue>45</returnvalue>
       </para></entry>
      </row>

      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <indexterm>
         <primary>atan2</primary>
        </indexterm>
        <function>atan2</function> ( <parameter>y</parameter> <type>double precision</type>,
        <parameter>x</parameter> <type>double precision</type> )
        <returnvalue>double precision</returnvalue>
       </para>
       <para>
        Inverse tangent of
        <parameter>y</parameter>/<parameter>x</parameter>,
        result in radians
       </para>
       <para>
        <literal>atan2(1, 0)</literal>
        <returnvalue>1.5707963267948966</returnvalue>
       </para></entry>
      </row>

      <row>
       <entry role="func_table_entry"><para role="func_signature">
        <indexterm>
         <primary>atan2d</primary>
        </indexterm>
        <function>atan2d</function> ( <parameter>y</parameter> <type>double