# Acos

```block Acos "Output the arc cosine of the input"
equation
y = Modelica.Math.acos(u);

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Documentation(info = "<html>\n<p>\nThis blocks computes the output <strong>y</strong> as the\n<em>cosine-inverse</em> of the input <strong>u</strong>:\n</p>\n<pre>\n    y = <strong>acos</strong>( u );\n</pre>\n<p>\nThe absolute value of the input <strong>u</strong> need to\nbe less or equal to one (<strong>abs</strong>( u ) <= 1).\nOtherwise an error occurs.\n</p>\n\n<p>\n<img src=\"modelica://Modelica/Resources/Images/Math/acos.png\"\n     alt=\"acos.png\">\n</p>\n\n</html>"));
end Acos;

```