Regularized Beta Function
The regularized beta function is defined by
where B(z;a,b) is the incomplete beta function and B(a,b) is the (complete) beta function. The regularized beta function is sometimes also denoted I_z(a,b) and is implemented in the Wolfram Language as BetaRegularized [z, a, b]. The four-argument version BetaRegularized [z1, z2, a, b] is equivalent to I(z_2;a,b)-I(z_1;a,b).
See also
Beta Function, Incomplete Beta Function, Regularized Gamma FunctionRelated Wolfram sites
http://functions.wolfram.com/GammaBetaErf/BetaRegularized/, http://functions.wolfram.com/GammaBetaErf/BetaRegularized4/Explore with Wolfram|Alpha
WolframAlpha
More things to try:
References
Pearson, K. (Ed.). Tables of Incomplete Beta Functions, 2nd ed. Cambridge, England: Cambridge University Press, 1968.Referenced on Wolfram|Alpha
Regularized Beta FunctionCite this as:
Weisstein, Eric W. "Regularized Beta Function." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/RegularizedBetaFunction.html