<?xml version="1.0" encoding="utf-8"?>
<page xmlns="http://projectmallard.org/1.0/" type="guide" id="trigonometry" lang="en-GB">

    <info>
        <link type="guide" xref="index#equation"/>
    </info>

	<title>Trigonometry</title>
    
    <p>Trigonometry can be performed using the sin, cos, and tan <link xref="function">function</link>.</p>
    <example>
    <p>sin 45</p>
    </example>
    <p>The angle units used can be changed from the <guiseq><gui>Calculator</gui><gui>Preferences</gui></guiseq> menu. Trigonometry buttons are visible when in <link xref="mouse">Advanced mode</link>.</p>
    <p>Hyperbolic functions are available by adding "h" to the end of a function.</p>
    <example>
    <p>sinh 0.34</p>
    </example>
    <p>Inverse functions are entered either using the inverse symbol ⁻¹ (<keyseq><key>Ctrl</key><key>I</key></keyseq>) or the "a" form of the function. The following two equations are equivalent.</p>
    <example>
    <p>sin⁻¹ 0.5</p>
    <p>asin 0.5</p>
    </example>   
    <p>To enter <link xref="variable">π</link> with the keyboard use <keyseq><key>Ctrl</key><key>P</key></keyseq>.</p>
</page>
