ACOS logarithmic form

[Ángel Martin]

(04-29-2016 02:50 AM)Sylvain Cote Wrote:  

(04-29-2016 02:19 AM)Claudio L. Wrote:  Thanks for the link! Page 61 lists for ACOS the same formula as Wikipedia. Does this mean ACOS on the 15C returns the other values?
Can somebody run ACOS(2) on the 15C?

HP-15C S/N:2435A04214

Code:

FIX 9
SF 8
2
ACOS     [X: 0]
Re<>Im   [X: 1.316957897]

41Z Module, any revision:

Z, 2 = 2 + j0
ZACOS = 0 + 1.316957897E0

When I programmed the 41Z I had to delve into this one at length. I even found a bug in Free42 (that I was using to check the results) which Thomas duly corrected very promptly, interestingly in the inverse trigonometric functions. I don't remember how I came up with the right value selection, but it must have been by applying the branch definition criteria all across the chain of intermediate calculations; how else.