dbeta(x, a, b) pbeta(q, a, b) qbeta(p, a, b) rbeta(n, a, b)
a and b. dbeta gives the density,
pbeta the distribution function, qbeta the
quantile function and rbeta generates random deviates.
The Beta distribution has density
Equations will come with HTML3
for a > 0, b > 0 and 0 <= x <= 1.