to access the numerical derivative option
which approximates the first derivative
of an expression with respect to a variable at a value.
Next, enter an expression, the variable, and a value
separated by commas. For example, to find the first derivative of x3
at x = 2, enter
For f(x) = x3, f'(2) = 12.
Note: The value of the derivative is found by computing the slope of the line through
the points ( value- ,
f(value-) ) and
( value+ ,
for some very small number .
The value of can be changed in the
tolerance editor available by pressing
typically has a value of about 0.0001.
Though this method is less accurate than der1, it can be used
to evaluate any expression, including a single nesting of itself for calculating the