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Casio ClassPad II fx-CP400 User Manual

Page 52

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Chapter 2: Main Application

  52

Condition Judgment (judge, piecewise)

u “judge” Function

The “judge” function returns TRUE when an expression is true, and FALSE when it is false.

Problem

Operation

Is the following expression true or false?
1 = 1

TRUE

[judge] 1

= 1 w

Is the following expression true or false?
1 < 0

FALSE

[judge] 1

< 0 w

u “piecewise” Function

The “piecewise” function returns one value when an expression is true, and another value when the expression
is false.

The syntax of the “piecewise” function is shown below.

piecewise(, , [ ) ]
or
piecewise(, , , indeterminate> [ ) ]

Use the soft keyboard (

1) to input “piecewise” function according to the syntax shown below.

or

,

,
,

Problem

Operation

For the expression 0

t

x

(

x

= variable), return 1

when

x

is 0 or less, and 2 when

x

is greater than 0

or undefined.

[piecewise] 0

:X, 1 , 2 w

or
1 1 c 2 ef 0 :X w

For the expression 1

t

x

(

x

= variable), return 1

when

x

is 1 or less, and 2 when

x

is greater than 1.

1 1 c 2 ef 1 :X c 1

Angle Symbol (

)

Use this symbol to specify the coordinate format required by an angle in a vector.
You can use this symbol for a vector only.

Problem

Operation

Convert the polar coordinates

r

=

'

2 ,

θ = π /4 to

rectangular coordinates.

[1, 1]

Change the [Angle] setting to “Radian”.
[toRect]

[5 2 e,~7/ 4 )]w

Derivative Symbol (’)

A single derivative symbol indicates the first derivative of an equation in the format: ’.

Problem

Operation

Solve the differential equation

y

’ =

x

.

{

y

= 0.5 ·

x

2

+ const (1)}

+Y'=X,X,Yw

Important!

The “dSolve” function can solve differential equations up to three degrees, so a maximum of three derivative
symbols (

y

’’’) can be used. Executing a “dSolve” calculation that has more than three derivative symbols will

result in an Invalid Syntax error.