Basic Operation

Mode

The calculator has nine modes of operation - Scientific Mode, Basic Mode, Complex Mode, Base In Mode, Matrix Mode, Equation Solver, Graph and Unit Converter. The current mode is shown in the top right. To select a mode:

Press MODE
Select the mode

To toggle fraction mode, press (SHIFT + HYP). Fraction works only in Basic or Scientific mode.

Secondary Function

Each key is associated with a secondary function shown in yellow above the key. To select a secondary function:

Press SHIFT key
Press the key corresponding to the secondary function

Alternatively, the seondary function of each key can also be accessed by holding down the key.

Angle Units

The calculator supports degree, radian and grade. The current angle unit is shown on the display at the top.
To toggle the angle units, press DRG key.
To change a number from one angle unit to another, press ( SHIFT + DRG ) after entering the number in the input field.

Calculation History

The calculator stores the last hundred results alongwith the input expressions. Each time you press = key, the result is added to the history list. The calculation history can be accessed via the options menu.
Use normal click to select the result and long click (click and hold) to select the input expression.
The most recent result is stored in a special variable "Ans", which can be accessed by pressing ( SHIFT + = ).
History can be cleared using RESET in options menu.

Memory

The calculator has ten memory locations - one main memory M and nine additional memory locaions M₁, M₂, M₃, M₄, M₅, M₆, M₇, M₈, M₉.
MR recalls the value from the main memory M
MS stores the display value to the main memory M
M+ adds the display to the main memory M
M- or ( SHIFT + M+ ) subtracts the display from the main memory M
To read any of the additional memory locations, use RCL ( SHIFT + MR )
To store to any of the additional memory locations, use STO ( SHIFT + MS )
Memory can be cleared using RESET in options menu.

Complex Mode

This mode supports rectangular as well as polar form of complex numbers.
To represent complex numbers in polar form use ∠
Use abs to calculate magnitude of a complex number and arg to calculate the argument.

Getting result in rectangular or polar form

By default, result is shown in rectangular form (as shown at the top). Button rec/pol ( SHIFT + 5) toggles the output between polar and rectangular form.

Matrix Mode

To enable matrix mode, press MODE and select Matrix.
The calculator supports matrix upto the order of 9 x 9. You can use the navigation keys to move across the matrix cells. You can also touch a matrix cell to select it.

Initializing matrix

Press dim ( SHIFT + 7 )
Select matrix (Press 1 for Matrix A, 2 for Matrix B, 3 for Matrix C)
Enter dimensions of the matrix and press OK ( SHIFT + DEL )
Pressing = stores the data from the input field in the selected matrix cell
The matrix is automatically saved each time you press =
Press AC to return to the main screen

Editing matrix

Press data ( SHIFT + 8 )
Select matrix (Press 1 for Matrix A, 2 for Matrix B, 3 for Matrix C)
Edit the matrix as desired. Each time you press = , the data of the selected matrix cell is over written
Press AC to return to the main screen

Using matrix in calculations

Press mat ( SHIFT + 9 )
Select matrix (Press 1 for Matrix A, 2 for Matrix B, 3 for Matrix C)
The selected matrix appears in the input field

Addtional matrix operations

trn ( SHIFT + 4 ) for calculating matrix transpose
inv ( SHIFT + 5 ) for calculating matrix inverse
det ( SHIFT + 6 ) for calculating matrix determinant

Equation Solver

The calculator can solve simultaneuos linear equations (upto 9 unknown variables) and polynomial equation (upto degree 9).
Press MODE and select EQUATION.
Press 1 for Simultaneous Linear Equations or 2 for Polynomial Equation.

Simultaneous Linear Equations

Enter the number of unknown variables and press OK ( SHIFT + DEL )
Enter the linear equations in the form of a coefficient matrix. Each row of the matrix corresponds to an equation and the columns correspond to the coefficients of the variables. The last column labeled "C" corresponds to the constant term on the right side of the equation.
After entering all the coefficients in the matrix, press solve ( SHIFT + 3 )

Polynomial Equation

Enter the degree of the equation and press OK ( SHIFT + DEL )
Enter the coefficients. a_i refers to the coefficient of the term containing xⁱ. For any xⁱ which is not present in the equation, enter 0 as coefficient.
After entering all the coefficients in the matrix, press solve ( SHIFT + 3 )

Graph

The calculator has an inbuilt graph plotter which is accessible via the button MODE. It can plot the graph of three equations simultaneously.

Draw graph

You can enter upto three funcitions - f(x), g(x) and h(x). f(x) is shown in yellow, g(x) in blue and h(x) in green.

To enter a function, tap on the corresponding input field. This will open the main calculator interface.
Now enter the function. Use the key X at the top row to enter the variable x.
Press = after entering the function
Click on DRAW after entering all the functions.

Additional Settings

You can initialize the graph so that the centre of the screen aligns with a given co-ordinate (x,y). By default, the graph is aligned with the origin (0,0)
Grid spacing allows you to set the spacing between the grids in the graph. You can enter any value you want.

Graph Operations

You can zoom the graph using the zoom keys at the bottom. Multi touch can also be used for zooming.
Tracing allows you to trace the co-ordinates of the graphs of the functions. Use the radio button at the bottom to toggle tracing mode. You cannot translate a graph while it is in tracing mode.

Unit Converter

The unit converter can be accessed via the button cnvt ( SHIFT + 3 ). The unit converter works only in Scientific, Complex and Matrix Mode.
To convert:

Press cnvt ( SHIFT + 3 ).
Select a category from the popup dialog.
Select the input unit.
Select the desired output unit.

HF Scientific Calculator 5.5