Section 2: Working With; Numerical Integration Using |7T - HP -15C Advanced Functions Handbook

Section 2
Working With
The HP-15C gives you the ability to perform numerical integration
using [7T|. This section shows you how to use | 7 T| effectively and
describes techniques that enable you to handle difficult integrals.
Numerical Integration Using f/T|
A calculator using numerical integration can almost never
calculate an integral precisely. But the [7T| function asks you in a
convenient way to specify how much error is tolerable. It asks you
to set the display format according to how many figures are
accurate in the integrand f(x). In effect, you specify the width of a
ribbon drawn around the graph of f(x). The integral estimated by
[7T| corresponds to the area under some unspecified graph lying
entirely within the ribbon. Of course, this estimate could vary by as
much as the area of the ribbon, so (7T| estimates this area too. If /is
the desired integral, then
_ area under a graph \
/ y
z
area of \n in the ribbon / \the
The HP-15C places the first area estimate in the X-register and the
second — the uncertainty — in the Y-register.
f(x)
f ( x )
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