HP 40G manual Finding derivatives, To find derivatives, GG@$/3+$@S1, Evaluate the function

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:

dx( sin (x 2 ) + 2 cos (x) )

1.Enter the differentiation function onto the command line, substituting S1 in place of X.

>G￿G[@￿>$/3+$@￿S1

>￿@￿>6,1@￿>$/3+$@￿S1￿ >[￿@ >￿@￿>￿@￿2 >[@ >&26@￿>$/3+$@￿S1 >￿@ >￿@

2.Evaluate the function.

>(17(5@

3.Show the result.

*k,￿6+2:_￿

HP 39G HP 40G

Using mathematical functions 10-23