A function programmed as an equation is usually included as an expression specifying the integrand — though it can be any type of equation. If you want the equation to prompt for variable values instead of including INPUT instructions, make sure flag 11 is set.

4.End the program with a RTN. Program execution should end with the value of the function in the X–register.

Example: Program Using Equation.

The sine integral function in the example in chapter 8 is

Si(t) = t

(

sin x

)dx

 

0

 

x

 

 

This function can be evaluated by integrating a program that defines the integrand:

  

Defines the function.

 

The function as an expression. (Checksum and length:

 

0EE0 8).

 

Ends the subroutine

Checksum and length of program: D57E 17

Enter this program and integrate the sine integral function with respect to x from 0 to 2 (t = 2).

Keys:

Display:

(In RPN mode)

 

9(2)

 

S  _

X



 

 



9(1)



Description:

Selects Radians mode.

Selects label S as the integrand. Enters lower and upper limits of integration.

Integrates function from 0 to 2; displays result.

Restores Degrees mode.

Solving and Integrating Programs 15-9