HP 39g+ - Manual (Page 159)

Using mathematical functions 10-23
Finding derivatives
The HP 39G/40G can perform symbolic differentiation on
some functions. There are two ways of using the HP 39G/40G
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.
>GG[@ >$/3+$@ S1
> @ >6,1@ >$/3+$@ S1
>[@ > @ >@ 2 >[@
>&26@ >$/3+$@ S1
> @ > @
2. Evaluate the function.
>(17(5@
3. Show the result.
*k,
TCPX•Ã
dx x
( 2 )
sin
(
2 x
( ) )
cos +
HP 39G HP 40G