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Hyperbolic Trig Functions for HP-10C

sinh, cosh and tanh functions, bummed just enough to require the conversion of only two registers into program steps.

[edit] Usage

• Enter program listed below
• for sinh:
  argument [R/S]
• for cosh:
  argument [GTO] [0] [6] [R/S]
• for tanh:
  argument [GTO] [1] [3] [R/S]

sinh and cosh require two stack levels, tanh requires 3. The program requires 23 steps including 9 base program steps and two converted data registers for 7 steps each. Registers R₀ through R₇ remain, leaving the user the desired statistics registers available, as well as two general-purpose registers.

[edit] Program Code

Addr	Code	Instruction	Comment
sinh entry
01	12	ex	ex
02	36	ENTER	e-x
03	15	1/x
04	30	-	ex - e-x
05	22 10	GTO 10	Branch to common denominator code
cosh entry
06	12	ex	ex
07	36	ENTER	e-x
08	15	1/x
09	40	+	ex + e-x
Common denominator code
10	2	2	(ex ∓ e-x) / 2
11	10	÷
12	22 00	GTO 00	reset program counter and halt
tanh entry
13	12	ex	e2x
14	42 11	x2
15	36	ENTER	need e2x in numerator and denominator
16	36	ENTER	need manual stack lift
17	1	1	e2x - 1 numerator
18	40	-
19	34	x↔y	Move numerator to Y register, work on denominator in X register
20	1	1	e2x + 1 denominator
21	30	+
22	10	÷	(e2x - 1) / (e2x + 1)
23	22 00	GTO 00	reset program counter and halt

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