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Derivatives on HP 42S
08-24-2018, 02:51 AM
Post: #12
RE: Derivatives on HP 42S
Hi Thomas,

When trying a more complicated equation: x^(4/3) + 4(x^(1/3)), I get a correct f(x) for all values of x (x=-6, f(x)=3.63, x=-4, f(x)=0 x=0, f(x)=0 x=2, f(x)=7.56)

Instead of a min at x=-1, f(x)= -3, my dx program comes up with a min at x=-3.

I know that this is probably not a concise program for FX, but it does work for this example. Why is DX not working?

LBL FX
STO X
4
Y^X
3
1/X
Y^X
STO B
RCL X
SIGN
STO S
RCL X
*
3
1/X
Y^X
4
*
ABS
RCL S
*
RCL B
+
END

LBL DX
MVAR A
MVAR H
RCL A
RCL H
COMPLEX
XEQ FX
COMPLEX
END

Thanks for your time!
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Messages In This Thread
Derivatives on HP 42S - lrdheat - 08-20-2018, 03:03 AM
RE: Derivatives on HP 42S - Thomas Klemm - 08-20-2018, 04:38 AM
RE: Derivatives on HP 42S - Thomas Klemm - 08-20-2018, 07:43 AM
RE: Derivatives on HP 42S - Albert Chan - 08-20-2018, 11:54 PM
RE: Derivatives on HP 42S - lrdheat - 08-20-2018, 10:57 PM
RE: Derivatives on HP 42S - Thomas Klemm - 08-20-2018, 11:43 PM
RE: Derivatives on HP 42S - Thomas Klemm - 08-21-2018, 12:34 AM
RE: Derivatives on HP 42S - Thomas Klemm - 08-21-2018, 01:35 AM
RE: Derivatives on HP 42S - lrdheat - 08-21-2018, 02:24 AM
RE: Derivatives on HP 42S - Thomas Klemm - 08-21-2018, 06:14 AM
RE: Derivatives on HP 42S - RMollov - 08-23-2018, 12:58 PM
RE: Derivatives on HP 42S - lrdheat - 08-24-2018 02:51 AM
RE: Derivatives on HP 42S - Thomas Klemm - 08-24-2018, 05:52 AM
RE: Derivatives on HP 42S - lrdheat - 08-25-2018, 05:19 PM
RE: Derivatives on HP 42S - Albert Chan - 08-25-2018, 07:03 PM
RE: Derivatives on HP 42S - Thomas Klemm - 08-25-2018, 06:05 PM
RE: Derivatives on HP 42S - Thomas Klemm - 08-25-2018, 08:00 PM
RE: Derivatives on HP 42S - Albert Chan - 08-25-2018, 09:20 PM
RE: Derivatives on HP 42S - Thomas Klemm - 08-26-2018, 04:54 AM
RE: Derivatives on HP 42S - Thomas Okken - 08-26-2018, 01:54 PM
RE: Derivatives on HP 42S - lrdheat - 08-26-2018, 04:47 PM
RE: Derivatives on HP 42S - Albert Chan - 08-26-2018, 08:39 PM
RE: Derivatives on HP 42S - Thomas Klemm - 08-26-2018, 08:00 PM
RE: Derivatives on HP 42S - Albert Chan - 08-29-2018, 01:52 PM



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