Diff Menu - HP 40gs User Manual

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DERIV
DERVX
14-16
Derivative and partial derivative
DERIV has two arguments: an expression (or a function)
and a variable.
DERIV returns the derivative of the expression (or the
function) with respect to the variable given as the second
parameter (used for calculating partial derivatives).
Example
Calculate:
2 3
∂ x y ( ⋅ ⋅ x y ⋅
z +
--------------------------------------------- -
∂z
Typing:
2
DERIV(X·Y ·Z
gives:
2 2
⋅ ⋅ ⋅
3 x y z
Derivative
DERVX has one argument: an expression. DERVX
calculates the derivative of the expression with respect to
the variable stored in VX.
For example, given:
x
f x ( )
------------- -
=
2
x – 1
calculate the derivative of f.
Type:
X
⎛
-------------- -
DERVX
⎝
2
X – 1
Or, if you have stored the definition of f(x) in F, that is, if
you have typed:
X
⎛
-------------- -
TORE
⎝
2
X – 1
then type:
)
3
+ X·Y,Z)
x + 1
⎛ ⎞
----------- -
+ ln
⎝ ⎠
x 1 –
X + 1
⎛ ⎞ ⎞
------------ -
+ LN
⎝ ⎠ ⎠
X 1 –
X + 1
⎛ ⎞ F , ⎞
------------ -
+ LN
⎝ ⎠ ⎠
X 1 –
Computer Algebra System (CAS)