HP -34C Owner's Handbook Manual page 236

234 Advanced Use of
The approximation of J(x) calculated by has an uncertainty that is
returned in the Y-register. Whenever the magnitude of Jy(x) is less than
this uncertainty, Jo(x) can be considered to be zero. By using this
technique, you can prevent from seeking unreasonable accuracy.
Slide the PRGM-RUNswitch to prom [[[[Illl . Key in a subroutine that
calculates Jo(x) and a subroutine that calculates the function to be
integrated.
Keystrokes Display
(1] CLEAR 000- Clear program memory.
™) @) 001-25, 13, 11 Begin with
instruction.
0 002- 23 0 Store argumentx.
0 003- 0 } Limits of integration.
Mm@ 004- 2573
) 3 005- 14,72, 3 Calculate Jy(x).
™) 006- 25 34 Magnitude of Jy(x).
M 007- 14 41 } Return zero if
008- 34 Jo(x) < uncertainty.
@ 009- 15 61 } Restore Jo(x) if value
(n])(sTx) 010- 25 0 is nonzero.
(DG 011- 25 12
M 3 012- 25,13, 3
06N 013- 14 7
rRcL) 0 014- 24 0
9 015- 61 Calculate function
() (cos 016- 14 8 to be integrated.
mm 017- 25 73
= 018- 71
™) 019- 25 12
In order to shorten the time to find the desired root, initially specify
0 display mode forthe integration. After an approximate solution
has been found, specify a greater integration accuracy (by using 3).
Then let home in on the root using the more accurate function.
This procedure eliminates the need to integrate with great accuracy for
values of x not near the root, saving considerable time.