arccos1

arccos pi

W3C sample	WIRIS
	$π$

<math xmlns="http://www.w3.org/1998/Math/MathML">
  <apply>
    <arccos/>
    <cn>&#x003C0;</cn>
  </apply>
</math>

Author: Design Science, Inc. (E. Cannon, E. Tabacman, R.Miner)