HP Prime Graphing Calculator - Manual (Page 347)

Functions and commands 343
ODE Draws the solution of the differential equation y'=f(t,y) that
crosses the point (t0,y0), where the first argument is the
expression f(t,y), the second argument is the vector of
variables (abscissa must be listed first), and the third argument
is (t0,y0).
plotode(Expr,VectVar,VectInitCond)
App menu
Press D to open the
Toolbox menus (one of which
is the App menu). App
functions are used in HP
apps to perform common
calculations. For example, in
the Function app, the Plot
view Fcn menu has a
function called SLOPE that calculates the slope of a given
function at a given point. The SLOPE function can also be
used from the Home view or a program to give the same
results. The app functions described in this section are
grouped by app.
Function app functions
The Function app functions provide the same functionality
found in the Function app's Plot view under the FCN menu. All
these operations work on functions. The functions may be
expressions in X or the names of the Function app variable F0
through F9.
AREA Area under a curve or between curves. Finds the signed area
under a function or between two functions. Finds the area
under the function Fn or below Fn and above the function Fm,
from lower X-value to upper X-value.
AREA(Fn,[Fm,]lower,upper)
Example:
AREA(-X,X 2 -2,-2,1) returns 4.5