Storing and recalling variables, Numeric Precision

Storing and recalling variables

Numeric Precision

You can store numbers or expressions from a previous input or result into variables.

A number stored in a variable is always stored as a 12-digit mantissa with a 3-digit exponent. Numeric precision in the display, however, depends on the display mode (Standard, Fixed, Scientific, Engineering, or Fraction). A displayed number has only the precision that is displayed. If you copy it from the HOME view display history, you obtain only the precision displayed, not the full internal precision. On the other hand, the variable Ans always contains the most recent result to full precision.

To store a value	1.	On the command line,
		enter the value or the
		calculation for the result
		you wish to store.
	2.	Press 672a?a
	3.	Enter a name for the
		variable.
	4.	Press >(17(5@.

11-2	Variables and memory management

Page 164

Image 164

HP 40G manual Storing and recalling variables, Numeric Precision, To store a value

Contents

USER’S Guide Page Contents Parametric aplet Inference aplet Importing Sample Statistics from the Statistics aplet Variables and memory management Programming Index Preface Manual conventions@, &26@, +20@, etc +,7@CLEAR, 6+,7@MODES, 6+,7@ACOS, etc Preface Home On/off, cancel operationsGetting started Parts of the display To adjust the contrast To clear the displayDisplay Annunciator Description KeyboardMenu keys Aplet control keys Key Meaning +,7@ $/3+$@175@ 75@ Shifted keystrokes HelpwithKey Description +,7@$/3+$@ Program commands Inactive keys Math keys To search a menu To cancel a menuMenus Mode settings Reset input form valuesSetting Options Input forms Setting Options Press+20@ to return to Home Setting a modeAplets E-lessons Aplet Use this aplet to explore Name Quad Explorer aplet N T Trig Explorer aplet *,*A, keys Symbolic view Plot view Numeric view Aplet libraryAplet views Aplets are stored in the Aplet library Views menu contains the Plot-Table view Aplet view configuration Plot Setup Numeric Setup SymbolicConfiguration To change views Mathematical calculations Entering expressionsLong results Negative numbers Example @4 6+,7@EEX @13@ @@6 6+,7@EEX 23@ j@ 3 6+,7@EEX 175@ Scientific notation powersExplicit and implicit multiplication Entering Calculates @ 45 @6+,7@π+,7@√ 85@9 +,7@√ @85 @9 @ Clearing numbers Using previous results 175@ updates ANS from 50 to 75 to 50175@ @25 175@175@ Key Function Accessing the display history$/3+$@ a 175@ Using fractions Setting Fraction modeSee Setting fraction precision below for more information Clearing the display history Setting fraction precision Fraction calculations Converting decimals to fractions Return to Home and enter the calculation@@@2@3 Evaluate the calculation Complex numbers Converting a number to a fractionComplex results To enter complex numbers + iy Storing complex numbers Catalog/Editor ContentsCatalogs and editors Differences between the HP 38G and the HP 39G/40G Memory manager Plot Goto functionStatistics Pred function Trig Explorer and Quadratic Explorer apletsPage About the Symbolic view Defining an expression Symbolic viewAplets and their views Aplet views Aplets and their views Home Evaluating expressionsAplets Symb view keys $56@$7+@ +,7@CLEAR Setting up the plot Plot view setup Plot view settingsAbout the Plot view 175@ or Reset plot settings +,7@*A Exploring the graphPlot view keys Trace a graph Zoom within a graphTo jump directly to a value To turn trace on/ off Zoom options Divides horizontal scale only, using Multiplies horizontal scale, usingDivides vertical scale only, using Multiplies vertical scale only, using 018Zoom =220Un-zoomPress *k, to move to the bottom of the Zoom list =220Zoom Out =220X-Zoom =220X-Zoom Out=220Y-Zoom =220Y-Zoom Out To box zoom To set zoom factors Other views for scaling and splitting the graph Options Menu key copies the right plot to the left About the numeric view Overlay plotsDecimal scaling Integer scaling Trigonometric scaling Reset numeric settings Setting up the table numeric view setupNumeric view settings Zoom within a table Exploring the table of numbersNUM view menu keys Building your own table of numbers Arrow keys to place the cursor in the independent variableColumn, then enter the value to jump to 175@, the values for the dependent variables are Build Your Own menu keys Clear data +,7@√@9 Example plotting a circle$3/7@ Select Function aplet About the Function apletGetting started with the Function aplet Open the Function aplet Define the expressions Plot the functions@75@175@ Plot the functions Change the scale Trace a graph With FCN functionsTrace the linear function Times Root value is displayed at the bottom of the screen Find the greater of the two roots of the quadratic functionSelectRoot 2Select.Slope Move the cursor to x = 1 by pressing the *A,orChoose the end value for @.2 Display the numeric view Set up the table Display the numeric setupTo find the extremum of the quadratic Display the numeric view Match the table settings to the pixel columns in the graph Explore the tableDisplay a table of numeric values Move to X = Function aplet interactive analysis Area Extremum Isect Root Slope Access FCN variables FCN functions Function Description Two selected expressions Symbolic view. DisplaysCursor. You need to have at least $3/ @ Select Plotting a piecewise defined function example=  Page Parametric aplet About the Parametric apletGetting started with the Parametric aplet Open the Parametric aplet Define the expressions 360 Set angle measure Set up the plot Plot the expression+,7@PLOT Overlay plot Display the numbers Plot a triangle graph over the existing circle graph+,7@ Plot 120Page Polar aplet Getting started with the polar apletOpen the Polar aplet +,7@CLEAR 46+,7@π 2.a Explore the graph Display the numbers Sequence aplet starts in the Symbolic view Sequence apletAbout the Sequence aplet Getting started with the Sequence aplet Define the expression Keys to assist in the entry of equations Plot Setup, set the Seqplot option to Cobweb Plot the sequence Display the tablePlot the Fibonacci sequence Select CobwebPage Solve aplet About the Solve aplet Define the equation Define known variables Getting started with the Solve apletOpen the Solve aplet @ Select Auto Solve the unknown variable Plot the equationSolve for the unknown variable a Solve aplet’s NUM view keys ≈20 times Use an initial guess Number format Interpreting results Message Condition Root- Finder at work Plotting to find guesses At2 x = v0t +$/3+$@X 180@ 30 175@ 2175@ *e,4175@ *e,*e, to highlight T Plot the graph To move cursor to the intersection Using variables in equations Home variablesInitial guess 3175@*k,*k,*k Statistics aplet About the Statistics apletGetting started with the Statistics aplet 1400 920 1100 2265 2890 2200 Open the Statistics aplet Enter data 175@1 175@ 175@5 175@ 175@4 175@To move to the next column 1400 175@920 175@ 1100 175@2265 175@ 2890 175@2200 175@ Select2. Linear Choose fit and data columns Explore statistics Setup plotSelect a fit in the Symbolic setup view Display the equation for the best linear fit To move to the FIT1 +2field Entering and editing statistical data $7+@ S to highlightTo highlight 6175@ Statistics aplet’s NUM view keys +,7@ FXUVRU 160 175@ 165 175@ 170 175@ 175 175@ 180 175@ $56@ Height cm Frequency Sets will need to be selected againBefore re-use Delete data Angle SettingSave data Defining a regression model 2VAR Insert data Sort data valuesTo choose the fit Select the Sort Order option. You can choose either Fit models To define your own fit Fit model Meaning= m lnx + b = ax3+bx2+cx+d. Needs at least Statistic Definition Computed statisticsOne-variable Two-variable Columns for a linear fit only You can plot PlottingTo plot statistical data Plot types Histogram Box and Whisker Plot Scatter Plot Relative Error Fitting a curve to0182VAR dataCorrelation Coefficient Setting up the plot Plot setup view Plotting mark 2VAR Connected points 2VAR Trouble-shooting a plot Statistics aplet’s Plot view keys Calculating predicted values Find predicted valuesPage Default the input form contains example data. This example Inference apletAbout the Inference aplet Example data Getting started with the Inference aplet Open the Inference apletInference aplet’s Symb view keys Hypothesis Tests Confidence Intervals Define the inferential method ∝.a∝ Field name Definition Open Statistics aplet. Note Reset current settings Importing Sample Statistics from the Statistics apletPlot test results Open the Statistics aplet Calculate statistics Open Inference aplet @529 175@ @295 175@ @952 175@ @259 175@ @925 175@ @592 175@ 2one.a Choose inference method and typeImport the data Display Numeric view Display Plot view Specify a 90% confidence interval in the C fieldE, to move to Field Display the confidence interval in the Plot view Hypothesis tests One-Sample Z-TestMenu name Inputs Result Description Two-Sample Z-TestResults One-Proportion Z-Test H0 π1 = π2 Two-Proportion Z-TestSuccesses in the two populations is equal One-Sample T-Test Test 1 ∝Selected hypothesis against the null hypothesis. The null Hypothesis is that the sample mean has some assumed value Two-Sample T-Test Sample 1 standard deviation Sample 2 standard deviation Confidence intervals Confidence interval calculations that the HP 39G/40G canPerform are based on the Normal Z-distribution or Student’s Confidence level Two populations, ∝1 ∝2, when the population standard Two-Sample Z-IntervalConfidence interval for the difference between the means Deviations, σ1 and σ2, are known One-Proportion Z-Interval Sample success count Two-Proportion Z-Interval Successes in two populationsSample 1 success count Sample 2 success count One-Sample T-Interval Two-Sample T-Interval Page Math menu Using mathematical functionsMath functions Calculus Loop Stat-Two Complex Matrices To select a functionFunction categories Functions common to keyboard and menus Math functions by categorySyntax Keyboard functions +,7@ASIN +,7@ACOS+,7@ATAN +,7@√ Valuepower +,7@ABSABSvalue +,7@ n Calculus functions TaylorVariableexpression Lower,upper,expression,variable Conj Complex number functionsARG Constants Hyperbolic trigonometry List functions AlogEXP EXPM1 Loop functions Matrix functionsIterate Recurse Polynomial functions PolycoefPolyeval Polyform Probability functions CombPerm Random Utpc UtpfUtpn Utpt Real-number functions HMS→ →HMSINT Mant MOD ChangeTotal RAD→DEG Statistics-Two SignTruncate Xpon Symbolic functions IsolateLINEAR? Quad Quote Trigonometry functions Symbolic calculations Symbolic calculations in the Function apletUsing formal variables Home Finding derivatives To find derivativesGG@$/3+$@S1 Evaluate the function To find derivatives in the Function aplet’s Symbolic view GG@@$/3+$@ To find the indefinite integral using formal variables +,7@GG@0 @ $/3+$@ S1 @ 3 @Show the result format Thus, substituting X for S1, it can be seen that 10-26 Variables and memory management Introduction To store a value Storing and recalling variablesNumeric Precision To store the results of a calculation Vars menu To use variablesCalculations 65 @$/3+$@A 175@ Names or values of variables into programs +,7@LIST 2contents,.a is copied to the command line $56@ *e,*e,*e,*A$/3+$@L3175@ List names directly from the keyboard Category Available names To copy the value of the variable into the edit line To access an aplet variableAplet variables Memory Manager Start the Memory Manager. a list of variable categoriesIs displayed +,7@MEMORYPage Matrices VectorsMatrices Matrix Variables Creating and storing matrices Matrix Catalog keys+ 7@CLEAR +,7@*e, or To create a matrix in the matrix catalog Select the type of matrix to create Working with matrices To transmit a matrixClears all elements from the matrix +,7@*k, *e 728 672? Matrix arithmetic To multiply and divide by a scalar175@ 2175@*e 175@ 4175@ 175@ 8 175@ $/3+$@M1@ $/3+$@M2 175@ $/3+$@M1 j@$/3+$@M2 175@ Solving systems of linear equations +,7@MATRIX1 175@175@7 175@ +,7@MATRIX Matrix functions and commands About functions Argument conventions Eigenval EigenvvIdenmat Inverse Rank RownormRref Schur Examples TraceTRN Identity Matrix Transposing a Matrix Reduced-Row Echelon Form Lists Creating listsCreate a list in the List Catalog Open the List catalog List catalog keys Create a list List edit keys Displaying and editing lists To display a listTo display one element To edit a list @ /@ 16a*e To insert an element in a list To store one element Deleting lists Transmitting listsTo delete a list To delete all lists List functions $/3+$@L 5175@ $7+@L *A $/3+$@L5175@$7+@L *A,Select $/3+$@A @ Calculates the product of all elements in list POSlist, elementCalculates the number of elements in a list Sorts elements in ascending order $/3+$@ L1 175@ Finding statistical values for list elements89@65@ 0@89 180@67$76a Go to the Numeric view To display calculated statisticsPage Aplet note view To write a note in Note view+,7@letter Your work is automatically saved. Press any view key +,7@%.63$= +,7@ Cmds To draw a line Aplet sketch viewSketch keys Where you want any corner of the box to be You can adjust the size of the box by moving the cursorTo draw a box Draw keys Highlight2. the variable name you want to use and press KeysPress 2.again to affix the label To import a graphics variable To create a note+,7@NOTEPAD Name of the note is ‘MYNOTE’ Opens the selected note for Begins a new note, and asks forTransmits the selected note to Another HP 39G/40G or PC 14-8 Contents of a Program Structured Programming Programming Program catalog Open Program catalog Program catalog keys +,7@*k, or *e Creating and editing programs Create a new program Enter commands Edit a program +,7@CMDSA,*e To enter functions more to come Editing keys Run a program From HOME, type RUN programname. or Using programsDebug a program Stop a program Working with programs Copy aProgram Transmit a program Delete a program Delete the contents of a program About customizing an apletDelete all Programs $3/7@Select Aplet naming conventionCustomizing an aplet example Configuring the Setviews menu option programs Setviews ’’’’’’’’18 Programming 15-13 Programming commands Aplet commandsCheck Select Command syntax Syntax for the command is as follows Auto-run programs Branch commands UncheckIF...THEN...END If test-clause Iferr trap-clause Then error-clause END IF... thenELSE... END CASE...END Iferr Then END Drawing commands Graphic commands →GROB GrobnotGrobor Grobxor Loop commands Matrix commands Randmat RedimScale Scaleadd Print commands Prompt commands Disp DisptimeDisp linenumbertextitem Editmat matrixname Input Input nametitle,labelhelpdefaultGetkey Msgbox PromptWait Wait seconds Stat-Two commands Stat-One and Stat-Two commandsStat-One commands Storing and retrieving variables in programs Plot-view variablesArea Axes Coord ExtremumFastRes Grid Hwidth IndepInvCross Isect Nmin / Nmax RecenterRoot S1mark-S5mark Simult SlopeStatPlot Umin/Umax Tmin / Tmax TracingTstep Xcross Xtick YtickXmin / Xmax Ymin / Ymax Symbolic-view variables XzoomYzoom Angle X1, Y1...X9,Y9 X0,Y0 R1...R9, R0U1...U9, U0 E1...E9, E0 Digits Numeric-view variablesC1...C9, C0 Format NumColNumFont NumIndep NumRow NumStartNumStep NumType PageNum Extending aplets Creating new aplets based on existing aplets $/3+$@ C @ 175@ Aplet Keys$/3+$@ H 175@ $1@ $/3+$@ θ @ $3/ @Select 180@ 35 175@ Resetting an aplet Downloading e-lessons from the webSolve for the missing Length of the ladder is approximately 8.72 metres Sending and receiving aplets To transmit an aplet To delete an aplet Sorting items in the aplet library menu listTo sort the aplet list Canada Reference informationRegulatory information LED safety Warranty Reference information Resetting the HP 39G/40G To reset using the keyboard 21@ key To erase all memory and reset defaultsIf the calculator does not turn on Glossary Cross matrix1,matrix2 Batteries Operating temperature 0 to 45C 32 to 113FOperating details Category Available name Menu maps of the Vars menuHome variables are Function aplet variables User-namedModes Function aplet variables are Parametric aplet variables are Parametric aplet variablesPlot-FCN Polar aplet variables Polar aplet variables are Sequence aplet variables Sequence aplet variables are Solve aplet variables Solve aplet variables are Stat-One Statistics aplet variablesStatistics aplet variables are Menu maps of the Math menu Math functionsMath functions are Calculus Polynom = = Program constants Program commands Category Command +,7@ Memory Selected status messagesMessage Meaning Current screen Function value, root, extremumOr intersection is not visible Index Index Index Index Index Index Index Index Index Index Index Index Index