00calc3

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 * Classpad 330 Calculator **

How to Solve Equations
Go to the Main Screen
 * Either by clicking on Main in the main menu
 * Or by clicking on Main in the green icon bar

The __**solve**__ command is in and also in
 * the ACTION menu, ADVANCED submenu
 * the ACTION menu, EQUATION submenu

To Solve Equations

 * 1) Enter the __**solve**__ command,
 * 2) then the equation
 * 3) then a comma (from keypad or top row of virtual keyboard)
 * 4) then the variable we are solving for
 * 5) then press EXE

{If there is only one variable in the equation, you can leave out the comma and the variable at the end, but it is a good habit to get into to include this part each time.}

Use the boldface variables (eg //**x, y, z**//),
 * either from the keypad,
 * or from the top line of the virtual keyboard
 * or from the VAR section of the MTH tab or the 2D tab

Notice that solutions will be in either decimals or exact values, depending on whether you have the calculator in STANDARD mode or not.

Notice that multiple solutions will be listed when appropriate.

Notice that the calculator will display ** {No Solution} ** if there are no real solutions to the equation.

To Solve Inequations
The inequation symbols are in the OPTN section of the MTH tab and the 2D tab. Notice the slightly strange format of the less than or equal to sign.

Don't use the symbol in the next row down that looks a bit like a less than sign -- that is the symbol for angle in geometry.

Enter the inequation the same way you would enter an equation, include the comma and the variable to be solved for.

Notice in the second example, the answer is displayed in a slightly non-standard way.

The way to write this answer would be: math \big\{ x \leqslant -4, \; x \geqslant 4 \big\} math



To Make Y the Subject
The calculator will solve even if there are other variables or constants in the equation.

In the examples to the right, we make y the subject.

To Substitute a Value into an Equation
In the example to the right we answer the question: For the equation 3//**x**// + 2//**y**// = 14, Find //**y**// when //**x**// = 5

The "|" symbol is in the OPTN section of the MTH tab and the 2D tab.

The "|" symbol goes after the ")" at the end of the solve command.

Solving Trig Equations
The various trig functions are in the MTH tab, TRIG screen.

The general form of a Trig equation has an infinite number of solutions.

This will be shown using constn(1) on the calculator. When you write this, the constn(1) should be replaced with n which can be all integers.

The solution to this equation would therefore be: math \Big\{ x = \dfrac{ n\pi}{2} + \dfrac{\pi}{8} \qquad \text {for } n \in Z \Big\} math {Where Z is the set of integers} .