# Talk:Documentation/Calc Functions/ACOSH

SF Review Comments

- (1) Do we know why the ODFF states that this function should calculate the "principal value"?
- (2) The last line of the example table mentions ACOS rather than ACOSH.
- (3) Should the Arguments section state the error that arises for an out-of-range value?
- (4) In the Returns section, I might change "that is the number" to "that is the value" because the word "number" appears too often!

--Stevefanning (talk) 2020-09-06T17:05:10 (UTC)

RG Reply

- (1) We need to figure this out although logically it sound wrong correct me if thats not true but principal value is between _pi and pi whereas we can get infinity here
- (2) Corrected
- (3) I have added it in additional details just like other functions to follow format also in functions before I have done the same it appears that first one or two I made this error all ahead have format as per now
- (4) Done

--RonnieGandhi (talk) 2020-09-07T7:42:55 (UTC)

OH-> Steve

(1) Correct me if I'm wrong but since COSH is an even function (COSH(negative)= COSH(positive)) the ACOSH function could also return the negative value, hence the "principal value" to specify the positive value.

OH->RG

Time to remove the blue box on the top.

--Olivier Hallot 2020-09-07T13:55:26 (UTC)