HP 48gII Note, ‚N~„l, Functions DERIV and DERVX

command catalog (‚N~„l) or through option 2. LIMITS & SERIES… of the CALC menu (see above).

Function lim is entered in ALG mode as = to calculate the

limit lim f (x) . In RPN mode, enter the function first, then the expression

x→a

‘x=a’, and finally function lim. Examples in ALG mode are shown next, including some limits to infinity. [Note: not all lines will be visible when done with the exercises in the figures in this Chapter. The display header will cover the top lines in the calculator.]

The infinity symbol is associated with the 0key, i.e.., „è.

Functions DERIV and DERVX

The function DERIV is used to take derivatives in terms of any independent variable, while the function DERVX takes derivatives with respect to the CAS default variable VX (typically ‘X’). While function DERVX is available directly in the CALC menu, both functions are available in the DERIV.&INTEG sub- menu within the CALCL menu ( „Ö).

Function DERIV requires a function, say f(t), and an independent variable, say, t, while function DERVX requires only a function of VX. Examples are shown next in ALG mode. Recall that in RPN mode the arguments must be entered before the function is applied.

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