<doc>

<legacy_id>1074</legacy_id>

<name>acos</name>

<type>function</type>

<syntax>

<example>the acos of <i>number</i></example>

<example>acos(<i>number</i>)</example>

</syntax>

<library></library>

<objects>

</objects>

<synonyms>

</synonyms>

<classification>

<category>Math, Logic, &amp; Dates</category>

</classification>

<references>

<constant tag="pi">pi Constant</constant>

</references>

<history>

<introduced version="1.0">Added.</introduced>

</history>

<platforms>

<mac/>

<windows/>

<linux/>

<ios/>

<android/>

</platforms>

<classes>

<desktop/>

<server/>

<web/>

<mobile/>

</classes>

<security>

</security>

<summary><glossary tag="return">Returns</glossary> the arc cosine of a number, in radians.</summary>

<examples>

<example>acos(-1)</example>

<example>acos(cos(.3))</example>

<example>acos(field "Opposite" + field "Sine")</example>

</examples>

<description>

<p>Use the <b>acos</b> <control_st tag="function">function</control_st> to find the arc cosine of a number.</p><p/><p><b>Parameters:</b></p><p>The <i>number</i> is a number between -1 and 1, or an <glossary tag="expression">expression</glossary> that <glossary tag="evaluate">evaluates</glossary> to such a number.</p><p/><p><b>Value:</b></p><p>The <b>acos</b> function <glossary tag="return">returns</glossary> a number between zero and pi.</p><p/><p><b>Comments:</b></p><p>The arc cosine of <i>number</i> is an angle whose cosine is equal to <i>number</i>. In other words, <b>acos</b> is an <keyword tag="inverse">inverse</keyword> of the <function tag="cos">cos</function> <control_st tag="function">function</control_st>.</p><p/><p>The result of the <b>acos</b> function is <glossary tag="return">returned</glossary> in radians. To get this result in <glossary tag="degree">degrees</glossary>, use the following <control_st tag="function">function</control_st>:</p><p/><p> function acosInDegrees theMagnitude</p><p> return acos(theMagnitude) * 180 / pi</p><p> end acosInDegrees</p>

</description>

</doc>