Sech[z] gives the hyperbolic secant of z.

lhs := rhs assigns rhs to be the delayed value of lhs. rhs is maintained in an unevaluated form. When lhs appears, it is replaced by rhs, evaluated afresh each time.

Tanh[z] gives the hyperbolic tangent of z.

Zeta[s] gives the Riemann zeta function \[Zeta](s). Zeta[s, a] gives the generalized Riemann zeta function \[Zeta](s, a).

SQLConnectionInformation[conn] returns a list of information about the SQL connection.

MultinormalDistribution[\[Mu], \[CapitalSigma]] represents a multivariate normal (Gaussian) distribution with mean vector \[Mu] and covariance matrix \[CapitalSigma].

Converting power series to normal expressions. Power series in Mathematica are represented in a special internal form, which keeps track of such attributes as their expansion ...

Solving equations involving power series. Here is a power series. This gives an equation involving the power series.

Button[label, action] represents a button that is labeled with label, and evaluates action whenever it is clicked.

Fibonacci[n] gives the Fibonacci number F_n. Fibonacci[n, x] gives the Fibonacci polynomial F_n (x).