a>.
</div>
<div id="inc-beta-appendix" class="section level2" number="27.2">
<h2><span class="header-section-number">27.2</span> Incomplete Beta</h2>
<p>The incomplete beta function, <span class="math inline">\(\text{B}(x; a, b)\)</span>, is defined for <span class="math inline">\(x \in [0, 1]\)</span> and <span class="math inline">\(a, b \geq 0\)</span> such that <span class="math inline">\(a + b \neq 0\)</span> by <span class="math display">\[
\text{B}(x; \, a, b) \ = \ \int_0^x u^{a - 1} \, (1 - u)^{b - 