e="radio" name="ipol" id="i_2" checked value="Move"><label for="i_2">move a point.</label> &nbsp;
		<button type="button" style="width: 120pt;" onclick="undo_last_for_interpolation()"><nobr>Undo last</nobr></button>
		<button type="button" style="width: 120pt;" onclick="reset_all_for_interpolation()"><nobr>Reset all</nobr></button>
	</div>
	<div id="interpolation_formula" class="formula">
	</div>
	<p>
The matrix is called <a href="https://en.wikipedia.org/wiki/Vandermonde_matrix"><Span id="index_vandermonde