HP Prime Graphing Calculator - Manual (Page 425)

Functions and commands 419
trunc Given a value or list of values, as well as an integer n, returns
the value or list truncated to n decimal places. If n is not
provided, it is taken as 0. Accepts complex numbers.
trunc(Real, Integer) or trunc(List, Integer)
Example:
trunc(4.3)
gives
4
tsimplify Returns an expression with transcendentals rewritten as
complex exponentials.
tsimplify(Expr)
Example:
tsimplify(exp(2*x)+exp(x))
gives
exp(x)^2+exp(x)
type Returns the type of an expression (e.g. list, string).
type(Expr)
Example:
type("abc")
gives
DOM_STRING
unapply Returns the function defined by an expression and a variable.
unapply(Expr,Var)
Example:
unapply(2*x^2,x)
gives
(x)→2*x^2
valuation Returns the valuation (degree of the term of lowest degree) of
a polynomial. With only a polynomial as argument, the
valuation returned is for x. With a variable as second
argument, the valuation is performed for it.
valuation(Poly,[Var])
Example:
valuation(x^4+x^3)
gives
3
variance Returns the variance of a list or the list of variances of the
columns of a matrix. The optional second list is a list of
weights.
variance(List1, [List2]) or variance(Matrix)
Example:
variance({3, 4, 2}) returns 2/3