<A NAME=PRECISE>
<TITLE>PRECISE</TITLE></A>
<b><a href=r37_idx.html>INDEX</a></b><p><p>
<B>PRECISE</B> _ _ _ _ _ _ _ _ _ _ _ _ <B>switch</B><P>
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When the <em>precise</em> switch is on, simplification of roots of even
powers returns absolute values, a more precise answer mathematically.
Default is <em>on</em>.
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examples: </H3>
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sqrt(x**2);
X
(x**2)**(1/4);
SQRT(X)
on precise;
sqrt(x**2);
ABS(X)
(x**2)**(1/4);
SQRT(ABS(X))
</TT></PRE><P>In many types of mathematical work, simplification of powers and s
urds can
proceed by the fastest means of simplifying the exponents arithmetically.
When it is important to you that the positive root be returned, turn
<em>precise</em> on. One situation where this is important is when graphing
square-root expressions such as sqrt(x^2+y^2) to
avoid a spike caused by REDUCE simplifying
sqrt(y^2) to y when x is
zero.
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