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<a name="scalbn_002c-scalbnf_002c-scalbln_002c-scalblnf_002d_002d_002dscale-by-power-of-FLT_005fRADIX-_0028_003d2_0029"></a>
<h3 class="section">1.51 <code>scalbn</code>, <code>scalbnf</code>, <code>scalbln</code>, <code>scalblnf</code>—scale by power of FLT_RADIX (=2)</h3>
<a name="index-scalbn"></a>
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<a name="index-scalbln"></a>
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<p><strong>Synopsis</strong>
</p><div class="example">
<pre class="example">#include <math.h>
double scalbn(double <var>x</var>, int <var>n</var>);
float scalbnf(float <var>x</var>, int <var>n</var>);
double scalbln(double <var>x</var>, long int <var>n</var>);
float scalblnf(float <var>x</var>, long int <var>n</var>);
</pre></div>
<p><strong>Description</strong><br>
The <code>scalbn</code> and <code>scalbln</code> functions compute
<var>x</var> times FLT_RADIX to the power <var>n</var>.
efficiently. The result is computed by manipulating the exponent, rather than
by actually performing an exponentiation or multiplication. In this
floating-point implementation FLT_RADIX=2, which makes the <code>scalbn</code>
functions equivalent to the <code>ldexp</code> functions.
</p>
<br>
<p><strong>Returns</strong><br>
<var>x</var> times 2 to the power <var>n</var>. A range error may occur.
</p>
<br>
<p><strong>Portability</strong><br>
ANSI C, POSIX
</p>
<br>
<p><strong>See Also</strong><br>
<code>ldexp</code>
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