Fun with the Texas
Instruments TI-60
Notes:
1. I like to have the
user input all the values into the registers before running the program. This way, we can save program steps because
the calculator doesn’t have to stop to ask for inputs. Also, you don’t have to change all the values
for different problems. Finally, R/S can
be used for only output.
2. I keep register 0
(R0) out so that the user can have at least one register to store immediate
results in further calculations. I list
the minimum partition for each program.
Great Circle Distance (in miles)
Formula:
D = acos (sin ϕ1 * sin ϕ2 + cos ϕ1 * cos ϕ2 * cos (λ1 – λ2))
* 3959 * π/180
Note: for kilometers, replace 3959 with 6371.
Where:
ϕ1, ϕ2: Latitude of
locations 1, 2; north is positive, south is negative
λ1, λ2: Longitude of
locations 1, 2: east is positive, west
is negative
Store before running:
R1: ϕ1 as a decimal
(convert from DMS if necessary)
R2: λ1
R3: ϕ2
R4: λ2
Set the TI-60 in degrees mode.
Program (41 steps) – 2nd Part 5:
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PG
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OP
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Key
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PG
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OP
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Key
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00
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71
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RCL
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21
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04
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4
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01
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01
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1
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22
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54
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)
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02
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32
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SIN
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23
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33
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COS
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03
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65
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*
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24
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95
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=
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04
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71
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RCL
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25
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12
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INV
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05
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03
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3
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26
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33
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[COS] (COS^-1)
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06
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32
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SIN
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27
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65
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*
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07
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85
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+
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28
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03
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3
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08
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71
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RCL
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29
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09
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9
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09
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01
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1
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30
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05
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5
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10
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33
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COS
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31
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09
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9
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11
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65
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*
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32
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65
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*
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12
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71
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RCL
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33
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91
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π
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13
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03
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3
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34
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55
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÷
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14
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33
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COS
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35
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01
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1
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15
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65
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*
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36
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08
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8
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16
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53
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(
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37
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00
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0
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17
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71
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RCL
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38
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95
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=
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18
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02
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2
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39
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13
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R/S
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19
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75
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-
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40
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22
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RST
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20
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71
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RCL
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Example:
Los Angeles: ϕ =
34°13’ = 34.21666667°, λ = -(118°15’) = -(118.25°)
London: ϕ = 51°30’26”
= 51.50722222°, λ = -(0°7’39”) = -(0.1275°)
Result: 5431.617778
mi
Tip: For DMS-DD conversions: if you have a negative angle,
enter the angle without the negative sign, do the conversion DMS-DD, then press [ +/- ].
Impedance of a Series Resonance Circuit
This program gives both the magnitude and phase angle.
Impedance: Z = R +
j*(ω*L – 1/(ω*C))
Where: ω = 2*π*F
Magnitude: abs(Z)
Phase Angle: arg(Z)
Variables:
R = resistance ( Ω )
C = capacitor ( farads )
L = inductor ( henrys )
F = Frequency (Hz)
Store before running:
R1: R
R2: C
R3: L
R4: F
Set the TI-60 in degrees mode.
Program (35 steps) – 2nd Part 5:
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PG
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OP
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Key
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PG
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OP
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Key
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00
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02
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2
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18
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02
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2
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01
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65
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*
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19
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54
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)
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02
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91
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π
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20
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76
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1/x
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03
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65
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*
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21
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95
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=
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04
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71
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RCL
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22
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61
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STO
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05
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04
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4
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23
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05
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5
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06
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95
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=
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24
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71
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RCL
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07
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61
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STO
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25
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01
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1
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08
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05
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5
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26
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52
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X<>Y
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09
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65
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*
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27
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71
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RCL
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10
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71
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RCL
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28
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05
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5
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11
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03
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3
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29
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12
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INV
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12
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75
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-
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30
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38
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[P-R]
(R-P)
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13
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53
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(
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31
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13
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R/S
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14
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71
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RCL
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32
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52
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X<>Y
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15
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05
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5
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33
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13
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R/S
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16
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65
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*
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34
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22
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RST
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17
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71
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RCL
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|
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Example:
Input:
R1: R = 11.56 Ω
R2: C = 0.0002 F
R3: L = 0.018 H
R4: F = 72 Hz
Results:
Phase Angle (θ) = -14.12679136°
Magnitude = 11.92049981
Linear Interpolation
Given points (x0, y0) and (x1, y1) with x0 < x < x1,
we can estimate y by linear interpolation by:
y = ((x1 – x)*y0 + (x – x0)*y1)/(x1 – x0)
How good of an approximation depends on how close x0 and x1
are, and whether the curve that is being approximated is close to linear.
Store before running:
R1: x1
R2: y1
R3: x2
R4: y2
R5: x
Program (34 steps) – 2nd Part 5:
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PG
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OP
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Key
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PG
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OP
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Key
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00
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53
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(
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17
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01
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1
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01
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53
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(
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18
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54
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)
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02
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71
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RCL
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19
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65
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*
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03
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03
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3
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20
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71
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RCL
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04
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75
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-
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21
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04
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4
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05
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71
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RCL
|
22
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54
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)
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06
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05
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5
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23
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55
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÷
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07
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54
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)
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24
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53
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(
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08
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65
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*
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25
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71
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RCL
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09
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71
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RCL
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26
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03
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3
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10
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02
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2
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27
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75
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-
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11
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85
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+
|
28
|
71
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RCL
|
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12
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53
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(
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29
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01
|
1
|
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13
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71
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RCL
|
30
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54
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)
|
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14
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05
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5
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31
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95
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=
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15
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75
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-
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32
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13
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R/S
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16
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71
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RCL
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33
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22
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RST
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Example:
Input:
R1: x1 = 2
R2: y1 = 3
R3: x2 = 4
R4: y2 = 8
R5: x = 3
Result:
y = 5.5
Purchase of a Car:
How much can I afford?
The program will calculate the sticker price (price before
sales tax) of an automobile that you can afford. You give the term you want, the interest rate
you qualify for, the sales tax rate, and the maximum payment you can afford. This assumes that you don’t put any money
down.
Formulas:
A = P/I * (1 – (1 + I)^-N) / (1 + S)
A = sticker price of the car
P = monthly payment
I = monthly interest rate of the loan, in decimal. I = rate/1200
N = number of months.
N = years*12
S = sales tax rate, in decimal. S = sales tax rate/100
Input:
R1: number of
payments
R2: monthly interest
rate
R3: payment
R4: sales tax rate,
in decimal
Program (30 steps), 2nd Part 4:
|
PG
|
OP
|
Key
|
PG
|
OP
|
Key
|
|
00
|
71
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RCL
|
15
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45
|
y^x
|
|
01
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03
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3
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16
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71
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RCL
|
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02
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55
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÷
|
17
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01
|
1
|
|
03
|
71
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RCL
|
18
|
94
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+/-
|
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04
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02
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2
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19
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54
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)
|
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05
|
65
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*
|
20
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55
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÷
|
|
06
|
53
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(
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21
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53
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(
|
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07
|
01
|
1
|
22
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01
|
1
|
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08
|
75
|
-
|
23
|
85
|
+
|
|
09
|
53
|
(
|
24
|
71
|
RCL
|
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10
|
01
|
1
|
25
|
04
|
4
|
|
11
|
85
|
+
|
26
|
54
|
)
|
|
12
|
71
|
RCL
|
27
|
95
|
=
|
|
13
|
02
|
2
|
28
|
13
|
R/S
|
|
14
|
54
|
)
|
29
|
22
|
RST
|
Example:
Input:
R1: number of
payments = 60, (5 year term)
R2: monthly interest
rate = 0.05/12 = 0.004166667, (5% annual interest rate)
R3: payment = 400
R4: sales tax rate,
in decimal = 0.095, (9.5%)
Result: 19357.34
In this example, the highest sticker price that can be
afforded is $19,357.34 (before sales tax).
I enjoy programming with the TI-60, unlike most Texas
Instruments calculators that have keystroke programming, the TI-60 shows the
step and key code you have entered instead of advancing to the next step with
code 00.
Eddie
This blog is property of Edward Shore, 2018.
