To clear one variable memory of global variable and local variable memories, press j x and then choose memory.

Memory clear key

Press @ P to display the menu. To initialize the display mode, press 0. The parameters set as follows. Angular unit: DEG (See page 26.) Display notation: NORM1 (See page 26.) N-base: DEC (See page 44.)
<M-CLR> DISP MEMORY STAT RESET
To clear all variables (excluding local variables of saved equations, statistical data and STAT variables), press 1 y. To clear statistical data and STAT variables, press 2 y. To RESET the calculator, press 3 y. The RESET operation will erase all data stored in memory and restore the calculators default setting.
Chapter 2: General Information
Editing and Correcting an Equation

Cursor keys

Incorrect keystrokes can be changed by using the cursor keys (l r u d).
Enter 123456 then correct it to 123459. 1. Press j 123456.

NORMAL MODE 0. 123456_

2. Press y 9 e. 0. If the cursor is located at the right end 123459= of an equation, the y key will 123459. function as a backspace key. You can return to the equation just after getting an answer by pressing the cursor keys. After returning to the equation, the following operations are useful; @ l or @ r: To jump the cursor to the beginning or the end of equation.
Overwrite mode and insert mode
Pressing @ O switches between the two editing modes: overwrite mode (default); and insert mode. A rectangular cursor indicates preexisting data will be overwritten as you make entries, while a triangular cursor indicates that an entry will be inserted at the cursor. In the overwrite mode, data under the cursor will be overwritten by the number you enter. To insert a number in the insert mode, move the cursor to the place immediately after where you wish to insert, then make the desired entry. The mode set will be retained until @ O is pressed or a RESET operation is performed.

Delete key

To delete a number/function, move the cursor to the number/function you wish to delete, then press y. If the cursor is located at the right end of an equation, the y key will function as a backspace key.
Multi-entry recall function
Previous equations can be recalled in the NORMAL, STAT or CPLX mode. Up to 160 characters of equations can be stored in memory. When the memory is full, stored equations are deleted in the order of the oldest first. Pressing @ g will display the previous equation. Further pressing @ g will display preceding equations. You can edit the equation after recalling it. The multi-entry memory is cleared by the following operations: mode change, memory clear (@ P 1 y), RESET, N-base conversion.

Using variables in an equation or a program
Both global and local variables can be used directly in an equation or a program. Local variables are useful when you need to use variables such as X1 and X2 at the same time in another equation. The local variable names and their values can be saved in each equation. (See page 58.)
Using A (6) and A1 (0.0000125) from the last two examples, solve the expression. 1 1000A A1 1. Press j 1 k. Start entering the expression.

NORMAL MODE 0. 1_

Press @ v.
3. Press 0 - 1000 ; A e. The display returns automatically to the previous screen after you have chosen the local variable, and you can continue to enter the expression. You do not need k if you use a variable. However, the variable must be a multiplier.

0. 1A-1000A= 74000.

Using the last answer memory
The calculator always keeps the most recent answer in ANS memory and replaces it with the new answer every time you press an ending instruction (e, x etc.). You may recall the last answer and use it in the next equation.
Evaluate the base area (S = 32) and volume of a cylinder (V = 5S) using the last answer memory.
1. Press j 3 A @ s e. The area of the base is now calculated. The number 28.27433388 is held in ANS memory. 2. Press j 5 ; < e. You now have the volume of the cylinder.

0. 3= 28.27433388

0. 5Ans= 141.3716694
The last answer is cleared (i.e. set to 0) if you press the RESET switch, change the mode or memory clear operation (@ P 1 y), but not if you turn the calculator off.

Global variable M

Using the M memory, in addition to the features of global variables, a value can be added to or subtracted from an existing memory value.
Example $1503:Ma +)$250:Mb=Ma+250 )Mb5% M
Key operations jxM 150 k 3 m 250 m t Mk 5@ % @MtM

0. 450. 250. 35. 665.

m and @ M cannot be used in the STAT mode.
Using memory in each mode
Mode NORMAL STAT PROG EQN CPLX : Available : Unavailable ANS M A-L, N-Z, Local variables

Notes:

Calculation results from the functions indicated below are automatically stored in memories replacing any existing values. r , xy. R memory (r) memory () X memory (x) Y memory (y) Use of t or ; will recall the value stored in memory using up to 14 digits in accuracy.

If you wish to clear all memories, variables, files and data, or if none of the keys (including j) will function, press the RESET switch located on the back of the calculator. In rare cases, all the keys may cease to function if the calculator is subjected to strong electrical noise or heavy shock during use. Follow the instructions below to reset the calculator. Caution: The RESET operation will erase all data stored in memory and restore the calculator's default setting. 1. Press the RESET switch located on the back of the calculator with the tip of a ballpoint pen or similar object. Do not use an object with a breakable or sharp tip.
A display appears asking you to confirm that you really want to reset the calculator.
zALL DATA CL?z z YES[DEL] z z NO[ENTER]z z ALL DATA z z CLEARED! z z z NORMAL MODE 0.
Press y. All memories, variables, files and data are cleared. The display goes back to the initial display in the NORMAL mode. The calculator will revert to the very first settings that were made when you started to use the calculator for the first time. Or, to cancel the operation, press e.
When corruption of data occurs, the reset procedure may automatically be initiated upon pressing the RESET switch. Pressing @ P and 3 y can also clear all memories, variables, files and data as described above.

Chapter 3

NORMAL mode
NORMAL mode is used for standard scientific calculations, and has the widest variety of functions. Many of the functions described in this chapter are also available for use in other modes. Press b 0 to select the NORMAL mode. Differential/Integral functions, N-base functions, Solver functions and Simulation Calculation (ALGB) in this chapter are all performed in the NORMAL mode. In each example of this chapter, press j to clear the display first. If the FIX, SCI or ENG indicator is displayed, clear the indicator by selecting NORM1 from the SET UP menu. Unless specified, set the angular unit as DEG. (@ P 0)

Arithmetic operations

Example 45+2853= 18+6 = 158 42(5)+120= (510 )(410 )=
Key operations j 45 + 285 z 3 e ( 18 + 6 ) z ( 15 - 8 ) e

3.428571429 90.

42 k S 5 + 120 e 5` 3z 4` S 3e

1250000.

Chapter 3: Scientific Calculations

Constant calculations

Example 34+57= 45+57= 6825= 6840= Key operations Result

0.001RAND 0.001

random= 0.232
Function 5: SOLVE Enter the Solver function mode. (See page 52.)

Key operations I 5

6: sec Sexagesimal numbers are converted to seconds notation. (See page 46.) 7: min Sexagesimal numbers are converted to minutes notation. (See page 46.)

24 [ I 6

24sec 86400.

0[0[ 1500 I 7

001500min 25.
Differential/Integral Functions
Differential and integral calculations can only be performed in the NORMAL mode. It is possible to reuse the same equation over and over again and to recalculate by only changing the values without having to re-enter the equation. Performing a calculation will clear the value in the X memory. You can use both global and local variables in the equation. The answer calculated will be stored in the last answer memory. The answer calculated may include a margin of error, or an error may occur. In such a case, recalculate after changing the minute interval (dx) or subinterval (n). Since differential and integral calculations are performed based on the following equations, in certain rare cases correct results may not be obtained, such as when performing special calculations that contain discontinuous points. Integral calculation (Simpsons rule):
1 S=h{f (a)+4{f (a+h)+f (a+3h)++f (a+(N1)h)} 3 +2{f (a+2h)+f (a+4h)++f (a+(N2)h)}+f(b)} ba h= N N=2n a x b
Differential calculation:

f(x+ )f(x ) f(x)= dx

Differential function
The differential function is used as follows. 1. 2. 3. 4. 5. 6. Press b 0 to enter the NORMAL mode. Input a formula with an x variable. Press @ 3. Input the x value and press e. Input the minute interval (dx). Press e to calculate.
To exit the differential function, press j. After getting the answer, press e to return to the display for inputting the x value and the minute interval, and press @ h to recalculate at any point.
Example d/dx (x40.5x3+6x2) Key operations j ; X* m 4 - 0.5 ;X1+6; XA@3 2ee Result
^4-0.5+6 0. =z dx: 0.00001 ^4-0.5+6 d/dx= 50. ^4-0.5+6 d/dx= 130.5000029
x=2 dx = 0.00002 d/dx = ? x=3 dx = 0.001 d/dx = ?

e 3 e 0.001 e

* X memory is specified by pressing ; then the 3 key.

Integral function

The Integral function is used as follows. 1. 2. 3. 4. 5. 6. 7. Press b 0 to enter the NORMAL mode. Input a formula with an x variable. Press {. Input the starting value (a) of a range of integral and press e. Input the finishing value (b) of a range of integral and press e. Input the subinterval (n). Press e to calculate.

No. Constant Symbol c, c 0 G gn me mp mn m lu e h k Unit
Speed of light in vacuum Newtonian constant of gravitation Standard acceleration of gravity Electron mass Proton mass Neutron mass Muon mass Atomic mass unit-kilogram relationship Elementary charge Planck constant Boltzmann constant Magnetic constant Electric constant Classical electron radius Fine-structure constant Bohr radius Rydberg constant Magnetic flux quantum Bohr magneton Electron magnetic moment Nuclear magneton Proton magnetic moment Neutron magnetic moment
m s1 m3 kg1 s2 m s2 kg kg kg kg kg C Js J K1 N A2 F m1 m m m1 Wb J T1 J T1 J T1 J T1 J T1

B e N p n

Constant

Symbol

Muon magnetic moment Compton wavelength Proton Compton wavelength Stefan-Boltzmann constant Avogadro constant Molar volume of ideal gas (273.15 K, 101.325 kPa) Molar gas constant Faraday constant Von Klitzing constant Electron charge to mass quotient Quantum of circulation Proton gyromagnetic ratio Josephson constant Electron volt Celsius Temperature Astronomical unit Parsec Molar mass of carbon-12 Planck constant over 2 pi Hartree energy Conductance quantum Inverse fine-structure constant Proton-electron mass ratio Molar mass constant Neutron Compton wavelength First radiation constant Second radiation constant Characteristic impedance of vacuum Standard atmosphere

Example Key operations

c c, p N, L
Vm R F RK -e/me h/2me p KJ eV t AU pc M(12C) h Eh G0
JT m m W m2 K4 mol1 m3 mol1 J mol1 K1 C mol1 Ohm C kg1 m2 s1 s 1 T1 Hz V1 J K m m kg mol1 Js J s

kg mol1 m W m2 mK Pa

mp/me Mu

c, n c1 c2

V0 = 15.3 m/s t = 10 s V0 t + gt = ? m 2
j 15.3 k 10 + 2 @ Z k @ c 03 k 10 Ae

643.3325

Calculations Using Engineering Prefixes
Calculation can be executed in the NORMAL mode (excluding N-base), STAT mode and PROG mode using the following 12 types of prefixes.
Prefix E P T G M k m n p f a (Exa) (Peta) (Tera) (Giga) (Mega) (kilo) (milli) (micro) (nano) (pico) (femto) (atto) Operation @j0 @j1 @j2 @j3 @j4 @j5 @j6 @j7 @j8 @j9 @jA @jB Unit 1015 1018

AB=CD D=z

D= R L

20. 50. 50.

Values of the left-hand side of the equation Values of the right-hand side of the equation
The value shown on the display for the unknown variable does not have to be set to 0 to solve the equation. The answer is displayed on the top line and the values of the lefthand and right-hand sides of the equation appear below. 8. Press e. Returns you to the display for entering variables.
AB=CD A=z AB=CD C=z C= R L 2.5 4. 80. 80. 10.
9. Press d 8 e. Substitutes the value 8 for B. The cursor moves onto the next variable C. 10. Press @ h. You can find any unknowns in the same equation.

Important notes

There are several important points to remember when you use the solver function. To cancel calculation, press j when calculating! is displayed. Before entering the equation, the appropriate angular unit must be selected. The calculator uses Newtons method to solve equations. Due to this, there may be some equations that it fails to solve even though they are in fact solvable. (See page 123.) The calculator stops calculating when the values it has obtained for the left and right sides of the equation become very close. Thus in certain cases the solution it gives may not be the real answer. (See page 122.) In certain cases, the calculator may abort a calculation and display the message shown on the right. (See page - ERROR 02 121.)

CALCULATION

Simulation Calculation (ALGB)
This function enables you to find different solutions quickly using different sets of values in the same expression.
Entering an expression for simulation calculation
The simulation calculation is used as follows. 1. 2. 3. 4. Press b 0 to enter the NORMAL mode. Enter an expression with at least one variable. Press @ G. Enter the values of the variables. The calculation result will be displayed after entering the value for all used variables. You can use both global and local variables in your equation, but only local variables will be stored if you save the equation. (See page 58.) You need enter only the side of the equation that contains the variables. Performing simulation calculation will cause the variables memories to be overwritten with new values. The answer calculated will be stored in last answer memory. To exit simulation calculation, press j.

SAVE:TITLE?

SAVE:RING_
RING is entered as the file name.
Press e to save the equation. The display returns to the display before pressing f.
When saving an equation, local variables (including their values) used in the equation are saved at the same time.
Loading and deleting an equation
The procedures to retrieve (load) and delete an equation from memory are the same, except that you have to confirm that you wish to delete the equation. Retrieve or delete an equation as follows. 1. Press f and then 0 or 2 to retrieve (load) or delete.

DEL RING AREA-3 CIRCUIT

DEL has been selected.
Use d u to select the name of the file you wish to retrieve (or delete),and press e. The display asks for confirmation if you are deleting an equation. Press y to proceed with deletion or e to cancel the operation.
TITLE:RING DELETE[DEL] QUIT[ENTER]
If the equation being retrieved contains local variables, the local variable names and their values will be retrieved along with the equation. Any other equation on the display and local variables before the equation was retrieved are cleared.
The STAT mode is used to perform statistical calculations. Press b 1 to select the statistics mode. The seven statistical calculations listed below can be performed. After selecting the statistics mode, select the desired sub-mode by pressing the number key that corresponds to your choice. To change statistical sub-mode, reselect statistics mode (press b 1), then select the required sub-mode. 0 (SD) 1 (LINE) 2 (QUAD) 3 (EXP) 4 (LOG) : Single-variable statistics : Linear regression calculation : Quadratic regression calculation : Exponential regression calculation : Logarithmic regression calculation
5 (POWER) : Power regression calculation 6 (INV) : Inverse regression calculation
Chapter 4: Statistical Calculations
The following statistics can be obtained for each statistical calculation (refer to the table below):
Variables Contents Number of samples
Mean of samples ( x data)

n x Q sx

I00 I01 I02 I03 I04 I05 I06 I07 I08 I09 I0A I0B I20 I21 I22 I23
Sample standard deviation (x data) Population standard deviation ( x data)

Sum of samples (x data)

Sum of squares of samples (x data)
Mean of samples ( y data)

Data correction

Correction prior to pressing _ immediately after a data entry: Delete incorrect data with j, then enter the correct data.
Correction after pressing _: Use u d to display the data set previously entered. Press d to display the data set in ascending (oldest first) order. To reverse the display order to descending (latest first), press the u key. Each data set is displayed with X=, Y=, or N: (N is the sequential number of the data set).

Data set number

75. 3.

Data x Frequency

X=z Y=

4. 3. 3.

Data x Data y Frequency
Display and move the cursor to the data item to be modified by using u d, input the correct value, then press _ or e. To delete a data set, display and move the cursor to an item of the data set to delete by using u d, then press @ #. The data set will be deleted. To add a new data set, press j to exit the display of previously entered data and input the values, then press _.

Stat 0 [SD] 0.

DATA DATA 60

30 _ 40 , 2 _ 50 _

DATA SET= DATA SET= DATA SET=

1. 2. 3.

ddd 45 _ 3_ d 60 _

45. 3. 60.

Statistical Calculation Formulas
Type Linear Exponential Logarithmic Power Inverse Quadratic Regression formula y = a + bx y = a ebx y = a + b ln x y = a xb 1 y=a+b x y = a + bx + cx2
In the statistical calculation formulas, an error will occur if: The absolute value of an intermediate result or calculation result is equal to or greater than 1 10100. The denominator is zero. An attempt is made to take the square root of a negative number. No solution exists for a quadratic regression calculation.

x = x n

x = x1 + x2 + + xn

x2 nx2

x2 = x12 + x22 + + xn2

y2 ny2

y = y1 + y2 + + yn
xy = x1y1 + x2y2 + + xnyn

y2 = y12 + y22 + + yn2

Normal Probability Calculations
P(t), Q(t), and R(t) will always take positive values, even when t<0, because these functions follow the same principle used when solving for an area. Values for P(t), Q(t), and R(t) are given to six decimal places.

t = x x x

Standardization conversion formula
Statistical Calculations Examples

@P2y b_ 80 _ _ 75 , 3 _

DATA 50

DECAY :NORMAL PROGRAM?

Input M

PrintCURRENT MASS

Program code T=-(ln(MM)) 1.2118-4
Key operations ; T ; = S ( i ( @ v 1 z @ v 0 ) ) z 1.2118 ` S 4 e i 0 ; T e i 1 @ a YEARS ; e i 5 e

Print T PrintYEARS

The half-life of a radioactive isotope is the time required for half of its mass to decay.
4. 5. 6. Press j to return to the PROG mode menu. Press 0, select the program DECAY and press e. Enter 100 for M0 and 50 for M1.
DECAY :NORMAL ORIGINAL MASS M=?
The half-life of 14C is 5719.980034 years.

T= 5719.980034 YEARS

Delta-Y impedance circuit transformation
Transformation of a Y impedance circuit to an equivalent Delta impedance circuit and vice versa.
The Delta-Y transformation is defined by the following formula: Z2 R1 R Z1 = R2 R Z2 = R3 R Z3 = R1 Z1 Z3 Z1 Z2 R1 = Z Z 2 Z3 R2 = Z Z 3 Z1 R3 = Z R2 R3
where R = R1R2 + R2R3 + R3R1

where Z = Z1 + Z2 + Z3

Press b 0 to open a window for creating a NEW program. Type DELTAY for the title then press e. A NEW program called DELTAY will be created. Enter the program as follows. Program code Key operations i 1 ( 1 ) @ a DELTA s TO s Y ; e i 1 ( 2 ) @ a Y s TO s DELTA ; e i 2 ; X e i 8 ; X ; = 1 ; s i 9 @ a DTOY ; e i 8 ; X ; = 2 ; s i 9 @ a YTOD ; e i 6 @ a DTOY ; e

Print(1)DELTA TO Y

Print(2)Y TO DELTA

Input X If X=1 Goto DTOY

If X=2 Goto YTOD

Label DTOY

Program code Z=Z+Z+Z ; e e d
Key operations Z ; = @ v Z1 e + @ v d Z2 e + @ v d Z3 e e e
@ v d d d R1 e e ; = @ v 0 @ v 1 z ; Z e i 0 @ v 3 e i 3 e @ v d d d d R2 e e ; = @ v 1 @ v 2 z ; Z e i 0 @ v 4 e i 3 e @ d v ; v d d d d R3 e e ; = @ 2 @ v 0 z Z e

Print R Wait R=ZZZ

Print R End Label YTOD
i 0 @ v 5 e i 5 e i 6 @ a YTOD ; e ; @ 4 v R ; = @ v 3 v 4 + @ v @ v 5 + @ 5 @ v 3 e

R=RR+RR+RR

@ v 0 ; = ; R z @ v 4 e i 0 @ v 0 e

Print Z

Program code Wait Z=RR
Key operations i 3 e @ v 1 ; = ; R z @ v 5 e i 0 @ v 1 e i 3 e @ v 2 ; = ; R z @ v 3 e i 0 @ v 2 e i 5 e

Print Z Wait Z=RR

Print Z End
When the impedances Z1, Z2, Z3 of a delta impedance circuit are 70, 35, 140 respectively, obtain the impedances R1, R2, R3 of a Y circuit. 4. 5. Press j to return to the PROG mode menu. Press 0, select the program DELTAY and press e. The direction of transformation will be asked. 6. 7. Enter 70 for Z 1, 35 for Z2 and 140 for Z3.

Program code If S<100 Goto AGAIN
Key operations i 8 ; S i D 100 ; s i 9 @ a AGAIN ; e ; S ; = ; S k @ Y ( S 3 ) e i 8 ; N i G 6 ; s i 9 @ a SIX ; e i 8 ; N i G 3 ; s i 9 @ a THREE ;e ; Q ; = I 1 ( ; S k @ Y ; N ) e i 9 @ a DISPLAY ; e i 6 @ a SIX ; e ; ; + Y @ Q ; = I 1 ( S k @ Y( ; N 6 ) ) k @ Y 6 @ w 0 k @ 6 + @ w 0 k Y 3 e
S=S10^(-3) If N>6 Goto SIX

If N>3 Goto THREE

Q=ipart(Sx10^N)
Goto DISPLAY Label SIX Q=ipart(S10^(N-6))10^6 +random10^6+random10^3
Goto DISPLAY Label THREE Q=ipart(S10^(N-3))10^3 +random10^3
i 9 @ a DISPLAY ; e i 6 @ a THREE ; e ; ; + Y Q ; = I 1 ( S k @ Y( ; N 3 ) ) k @ Y 3 @ w 0 k @ 3 e
Label DISPLAY Clrt Print Q
i 6 @ a DISPLAY ; e i 7 e i 0 ; Q e
Program code Wait T Clrt PrintANSWER
Key operations i 3 ; T e i 7 e i 1 @ a ANSWER ; e i 2 ; X e

Input X

* If answer is correct, add (30 x number of digits / number of seconds) to score.

If X Q Goto WRONG

i 8 ; X i H ; Q ; s i 9 @ a WRONG ; e ; A ; = ; A + I 2 ( 10 k ; N z ; T k 3 ) e i 6 @ a WRONG ; e ; M ; = ; M + 1 e i 8 ; M i E 10 ; s i 9 @ a QUESTION ; e i 1 @ a YOUR s SCORE s IS ; e i 0 ;A e i 5 e

A=A+int(10NT3)

Label WRONG
M=M+1 If M<=10 Goto QUESTION

PrintYOUR SCORE IS

Print A End
4. 5. 6. 7. 8. 9. Press j to return to the PROG mode menu. Press 0, select the program NUMBER and press e. Enter the number of digits you wish to play with N. Enter the number of seconds to display the numbers. Immediately after you press e, the game will start. After ANSWER X=? is displayed, enter the number you remembered and press e. After 10 tries, the score is displayed.

Calculation Examples

Geosynchronous orbits
The orbit of a satellite about the Earth is geosynchronous if the period of the orbit matches the period of the Earths rotation. At what distance from the center of the Earth can geosynchronous orbit occur? The period of an orbit is described by the equation
42 T2 = r3 GM where T = period of orbit G = Gravitational constant (6.m3 kg1s2) M = Mass of the Earth (5.kg) r = Distance between the satellite and the center of the Earth (radius of orbit)

The Earth rotates once every 23 hours, 56 minutes and 4.09 seconds. At first, convert this time into seconds. 1. Press b [ 56 [ 4.09 [ I 6. Determining the value of T. 2. 3. Press x T to store the result as global variable T. Press @ J 4. Select the scientific display format with four significant digits. Use the solver function to solve the equation for r. 4. Press j ; T A ; = (4@sA)z( ; G ; M ) k ; R 1.

23564.09se c 86164.09

86164.09 AnsT 8.616

0.000 T=(4)(GM) R_

T=(4)(GM) R G=z 0.000
Check the equation on the display and press I 5 to enter the solver function.
Press @ c 02 e 5.976 ` 24 e. Use the physical constants function for the G value.

T=(4)(GM) R R=z 0.000

After completion of entering values for variables G and M, the cursor moves on to variable R. (The variable T has already its value.) 7. Press @ h.
Geosynchronous orbit is possible approximately 42,170 km (4.meters) from the center of the Earth.

R= R L

4.217 7.424 7.424
Twinkle, twinkle, little star (Apparent magnitude of stars)
The apparent magnitude of a star is a measure of how bright it appears. It is a function of how far away the star is and the luminosity of the star. Since stars are seen from different distances, their luminosities must be standardized before they can be compared. This is done using a quantity called the absolute magnitude, which is a measure of how bright that star would appear if it was viewed from a distance of 10 parsecs (about 32.6 light years). If the absolute magnitude of two stars is known, the ratio of their luminosities is given by the equation.
L2 Log = 0.4 (M1 M2) L1 where M1 = Absolute magnitude of the first star M2 = Absolute magnitude of the second star L1 = Luminosity of the first star L2 = Luminosity of the second star
What is the ratio of the suns luminosity to that of a star having an absolute magnitude of 2.89? (The suns absolute magnitude is 4.8.) The former equation is equivalent to L2 = 10 0.4 (M1 M2) L1

where M2 = 2.89

1. 2. Press b 0 and @ P 0. Press @ Y ( 0.4 k ( 4.8 - 2.89 ) ) e.
1^(0.4(4.8-2. 89))= 5.807644175
5.807644175 The star is nearly six times as luminous as the sun.

Press e. Do not press y. If y is pressed, the memory contents will be cleared.
10. Adjust the LCD contrast. (See page 118.)
Automatic power off function
The calculator will turn itself off to save battery power if no key is pressed for approximately 10 minutes.

The OPTION menu

The OPTION menu controls display contrast, memory checking and deletion of data.

The OPTION display

Press @ o (S key) to show the OPTION menu. Press j to return to the mode in which you were working previously.
<OPTION> CTRST M.CHK DELETE

Contrast

Press 0 in the OPTION menu to show the LCD CONTRAST display. Press + to darken the display and - to lighten it.
It is possible to lighten the display so much that the calculator appears to be off. If the display remains blank when you press X, press @ o 0 and then press + repeatedly to darken the display.

Memory check

Press 1 in the OPTION menu to show the MEMORY CHECK display. The amount of free memory in bytes is shown on the first line. When the calculator is used for the first time, the following amount of memory is available. [EL-5250] 4,096 bytes [EL-5230] 1,280 bytes The figures after EQTN are the numbers of equations (Filing equations functions) in the NORMAL mode. The figures after PROG are the numbers of programs stored in the PROG mode. For a detailed description of how memory is used, refer to Memory usage. (See page 126.)
624BYTES FREE EQTN: 15 PROG: 09
Deleting equation files and programs
Press 2 in the OPTION menu to show the DELETE menu. Press 0 or 1 to delete equation files or programs that have been stored in the NORMAL or PROG modes, respectively.
<<DELETE>> EQTN PROG
After selecting the mode for which data is to be deleted, press y to delete data. Press e to cancel the operation. Once a file has been deleted there is no way to recover it. To delete individual files, enter the mode that contains the data you want to delete and use the specific delete function from the menu. (See pages 59 and 86.)
If an Abnormal Condition Occurs
Should an abnormal condition occur, such as none of the keys (including j) functioning, press the RESET switch located on the back of the calculator. Refer to page 32.
The following table shows common error messages and suggestions for correcting the error.

Error no.

Error message
SYNTAX CALCULATION NESTING

Solution

Verify you are using the correct syntax for the function you are trying to apply. Check you have not attempted to divide by zero or made some other calculation error. Use of more than the available number of buffers was attempted. (There are 10 buffers* for numeric values and 24 buffers for calculation instructions.) * 5 buffers in the CPLX mode. Make sure your program does not use the same label name to specify more than one location. Make sure your program does not have a Goto or Gosub command pointing to a label that does not exist. Note that you can include labels that are not pointed to by Goto or Gosub commands without affecting program operation. Make sure your program does not have more than 20 labels. Make sure your program does not have more than 10 levels of nested subroutines. Make sure your program does not have a Return command with no corresponding Gosub command. Not enough free memory remains for what you are trying to do. Delete unneeded files and try again. Make sure the maximum number of 99 saved equations or 99 programs is not exceeded. Delete unneeded equations or programs and try again. Use of more than 100 data items in the STAT mode was attempted. The maximum number of 160 characters in the equation input buffer was exceeded. You have pressed j to stop a program or solver calculation.

LBL DUPLICATE

LBL UNDEFINED

LBL OVER GOSUB STACK

CANT RETURN

MEMORY OVER

STORAGE FULL

DATA OVER

(No number)
Using the Solver Function Effectively
The calculator uses Newtons method to solve equations. (See page 52.) Because of this, the solution it provides may differ from the true solution, or an error message may be displayed for a soluble equation. This section shows how you can obtain a more acceptable solution or make the equation soluble in such cases.

Newtons method

Newtons method is a successive approximation technique that uses tangential lines. The calculator chooses an approximate solution then calculates and compares the right-hand and lefthand sides of the equation. Based on the result of this comparison, it chooses another approximate solution. It repeats this process until there is hardly any discrepancy between the right-hand and left-hand sides of the equation.

y = f(x)

Tangential lines
Initial value Newtons method Intersections of dotted lines with the x-axis give successive approximate solutions found using Newtons method.

Dead end approximations

When @ h is pressed for the first time, the calculator takes the value that is stored in memory, or zero if no value is stored, to be the initial expected value for the unknown variable and tries to solve the equation. If it fails to find an acceptable solution using this expected value, it tries again using up to nine more initial expected values until a solution is found. If none of the values lead by successive approximation toward an - ERROR 02 acceptable solution but rather to a dead CALCULATION end the calculator will abort calculation and display an error message.

Range of expected values

After the stored value (or zero) has been tried, new initial expected values are selected according to the range of expected values for the equation. (See Changing the range of expected values.) To choose which initial expected values to try, the calculator divides the range into eight subranges of equal width and tries each of the values at the edges of these subranges in turn (starting with the lower limit of the range of expected values, a).

Calculation accuracy

The calculator solves an equation by comparing the values of the lefthand and right-hand sides of the equation through 14-digit internal operations. If the value of the left-hand side is sufficiently close to agreeing with that of the right-hand side the calculator may present one of the approximate values as a solution even though it is not the true solution. The calculator will also stop trying to solve an approximate solution either when it has performed more than 50 iterations using each initial expected value or when it has obtained an approximate solution that is the same (to 10-digit accuracy) twice in succession.