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(20S) and (21S) Numerical Derivative - Eddie W. Shore - 05-20-2019 12:58 PM
Numerical Derivative
f'(x0) ≈ ( f(x0 + h) - f(x0 - h) ) / ( 2*h )
x = point
h = small change of x, example h = 0.0001
LBL A: Main Progam
LBL F: f(X), where R0 acts as X
Input variables:
R1 = h
R2 = point x0
Used variables:
R0 = x (use R0 for f(x), LBL F)
Calculated Variables:
R3 = f'(x)
Radians mode will be set.
Program:
Code:
01 LBL A: 61,41A
02 RAD: 61,24
03 RCL 2: 22,2
04 +: 75
05 RCL 1: 22, 1
06 =: 74
07 STO 0: 21,0
08 XEQ F: 41,F
09 STO 3: 21, 3
10 RCL 2: 22,2
11 -: 65
12 RCL 1: 22,1
13 =: 74
14 STO 0: 21,0
15 XEQ F: 41,F
16 STO - 3: 21,65,3
17 2: 2
18 STO ÷ 3: 21,45,3
19 RCL 1: 22,1
20 STO ÷ 3: 21,45,3
21 RCL 3: 22,3
22 R/S: 26
23 LBL F: 61,41,F
...
xx RTN: 61,26 (end f(X) with RTN)Example: e^x * sin x
LBL F
RCL 0
e^x
*
RCL 0
SIN
=
RTN
R1 = 0.0001
R2 = x0 = 0.03
Result: 1.060899867
R1 = 0.0001
R2 = x0 = 1.47
Result: 4.7648049