HP 39g+, Руководство пользователя

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Using mathematical functions 11-21
Symbolic
calculations in the
Function aplet
You can perform symbolic operations in the Function
aplet’s Symbolic view. For example, to find the derivative
of a function in the Function aplet’s Symbolic view, you
define two functions and define the second function as a
derivative of the first function. You then evaluate the
second function. See “To find derivatives in the Function
aplet’s Symbolic view” on page 11-22 for an example.
Finding derivatives
The hp 39g+ can perform symbolic differentiation on
some functions. There are two ways of using the hp 39g+
to find derivatives.
•
You can perform differentiations in HOME by using
the formal variables, S1 to S5.
•
You can perform differentiations of functions of X in
the Function aplet.
To find derivatives
in HOME
To find the derivative of the function in HOME, use a
formal variable in place of
X
. If you use
X
, the
differentiation function substitutes the value that
X
holds,
and returns a numeric result.
For example, consider the function:
1. Enter the differentiation function onto the command
line, substituting S1 in place of
X
.
S1
S1
2
S1
2. Evaluate the function.
dx x
(
2
)
sin
(
2 x
( ) )
cos +