HP 49g+, Руководство пользователя, Страница: 435 / 862

Page 13-4
Out of these functions DERIV and DERVX are used for derivatives. The other
functions include functions related to anti-derivatives and integrals (IBP, INTVX,
PREVAL, RISCH, SIGMA, and SIGMAVX), to Fourier series (FOURIER),and to
vector analysis (CURL, DIV, HESS, LAPL). Next we discuss functions DERIV
and DERVX, the remaining functions are presented either later in this Chapter
or in subsequent Chapters.
Calculating derivatives with
∂
The symbol is available as
‚¿
(the
T
key). This symbol can be used
to enter a derivative in the stack or in the Equation Writer (see Chapter 2). If
you use the symbol to write a derivative into the stack, follow it immediately
with the independent variable, then by a pair of parentheses enclosing the
function to be differentiated. Thus, to calculate the derivative d(sin(r),r), use,
in ALG mode:
‚¿~„r„ÜS~„r`
In RPN mode, this expression must be enclosed in quotes before entering it
into the stack. The result in ALG mode is:
In the Equation Writer, when you press
‚¿
, the calculator provides the
following expression: