Special functions for any argument x

Description

The program calculates the values of four special functions for any argument x:
The program calculates these functions using the transformation u = e-t² whenever |x| > 1.6.

Example 1:

f SCI 3 20 f B → 2.753-89

1.234 f A → 8.914-01

Example 2:

For a Normally distributed random variable X with mean 2.151 and standard deviation 1.085, calculate the probability Pr [2 < X ≤ 3].

2 ENTER 2.151 - 1.085 ÷ f A → 4.447 (Pr[X ≤ 2])
STO 3 (Store value)

3 ENTER 2.151 - 1.085 ÷ f A → 7.830 (Pr[X ≤ 3])

RCL 3 → 4.447 (Recall value)
- → 3.384 (Pr[2 < X ≤3])
f FIX 4 → 0.3384

Program Resources

Labels

Name Description Name Description
 A Evaluate P(x)  2 #
 B Evaluate Q(x)  3 # Subroutine to divide by sqrt(π)
 C Evaluate erf(x)  4 # Subroutine for erf(x) or erfc(x)
 E Evaluate erfc(x)  5 # Calculates erfc(x)
 0 # Subroutine to calculate e^(-t³)  6 # Subroutine to integrate when |x| > 1.6
 1 # Subroutine to calculate (ln u)^-1/2

Storage Registers

Name Description
 0
 1
 2

Flags

Number Description
1

Program

Line Display Key Sequence Line Display Key Sequence Line Display Key Sequence
000 028 42,21,15 f LBL E 056 16 CHS
001 42,21,11 f LBL A 029 0 0 057 12
002 44 2 STO 2 030 42,21, 4 f LBL 4 058 42,20, 1 f ∫xy 1
003 16 CHS 031 43, 5, 1 g CF 1 059 32 3 GSB 3
004 22 2 GTO 2 032 44 1 STO 1 060 45 0 RCL 0
005 42,21,12 f LBL B 033 34 x↔y 061 36 ENTER
006 44 2 STO 2 034 44 0 STO 0 062 43 16 g ABS
007 42,21, 2 f LBL 2 035 43 16 g ABS 063 10 ÷
008 2 2 036 1 1 064 20 ×
009 11 √x̅ 037 48 . 065 45 1 RCL 1
010 10 ÷ 038 6 6 066 43 36 g LSTΧ
011 32 13 GSB C 039 43,30, 8 g TEST x<y 067 30
012 2 2 040 22 6 GTO 6 068 40 +
013 10 ÷ 041 0 0 069 16 CHS
014 45 2 RCL 2 042 45 0 RCL 0 070 43 32 g RTN
015 44 0 STO 0 043 42,20, 0 f ∫xy 0 071 42,21, 0 f LBL 0
016 33 R⬇ 044 2 2 072 43 11 g
017 43 32 g RTN 045 20 × 073 16 CHS
018 42,21,13 f LBL C 046 42,21, 3 f LBL 3 074 12
019 1 1 047 43 26 g π 075 43 32 g RTN
020 32 4 GSB 4 048 11 √x̅ 076 42,21, 1 f LBL 1
021 43, 6, 1 g F? 1 049 10 ÷ 077 43 20 g x=0
022 22 5 GTO 5 050 43 32 g RTN 078 43 32 g RTN
023 1 1 051 42,21, 6 f LBL 6 079 43 12 g LN
024 30 052 43, 4, 1 g SF 1 080 16 CHS
025 42,21, 5 f LBL 5 053 0 0 081 11 √x̅
026 16 CHS 054 45 0 RCL 0 082 15 1/x
027 43 32 g RTN 055 43 11 g 083 43 32 g RTN