HP 35s HP 35s scientific calculator - User Guide - Page 244

Using Integration in a Program Integration can be executed from a program. Remember to include or prompt for the limits of integration before executing the integration, and remember that accuracy and execution time are controlled by the display format at the time the program runs. The two integration instructions appear in the program as:  label variable The programmed ∫ FN instruction does not produce a labeled display (∫ = value) since this might not be the significant output for your program (that is, you might want to do further calculations with this number before displaying it). If you do want this result displayed, add a PSE or STOP () instruction to display the result in the X-register after the ∫ FN instruction. If the PSE instruction immediately follows an equation that is displayed (Flag 10 set) during each iteration of integrating or solving, the equation will be displayed for 1 second and execution will continue until the end of each iteration. During the display of the equation, no scrolling or keyboard input is allowed. Example: ∫ FN in a Program. The "Normal and Inverse-Normal Distributions" program in chapter 16 includes an integration of the equation of the normal density function S 1 2π ∫ D M −( D−M ) 2 /2 e S dD. The e((D −M)÷S)2 ÷2 function is calculated by the routine labeled F. Other routines prompt for the known values and do the other calculations to find Q(D), the upper- tail area of a normal curve. The integration itself is set up and executed from routine Q: 15-10 Solving and Integrating Programs