Syntax:
BETA(a:Number, b:Number)
Returns the value of the Beta function for parameters a and b.
Formula:
One definition of the Beta function is
Β(a, b) = Γ(a) ⋅ Γ(b) ÷ Γ(a + b)
This special function is actually evaluated by Fireworkz using the formula
Β(a, b) = EXP( GAMMALN(a) + GAMMALN(b) − GAMMALN(a + b) )