Arccosine arc cosine Inverse Cosine -- from Wolfram MathWorld inverse cosine inverse cosine Inverse Cosine Inverse Cosine -- from Wolfram MathWorld http://mathworld.wolfram.com/InverseCosine.html «Arcocoseno» inverse cosine Arc (inverse) cosine, a description MathWorld MathWorld Inverse Cosine MathWorld page for arccosine function Inverse Cosine Inverse Cosine from Wolfram MathWorld Arc (inverse) cosine, a description arccosine