The ACOSH function returns the inverse hyperbolic cosine of a number. The number must be greater than or equal to 1. The inverse hyperbolic cosine is the value whose hyperbolic cosine is number, so ACOSH(COSH(number)) equals number.




Argument Description
number Any real number ≥ 1


  A B C
1 Formula Result Notes
2 =ACOSH(1) 0 Inverse hyperbolic cosine of 1
3 =ACOSH(2.5) 1.5667992 Inverse hyperbolic cosine of 2.5
4 =ACOSH(10) 2.9932228 Inverse hyperbolic cosine of 10

Common Function Error(s)

Problem What went wrong
#VALUE! Occurs if the supplied number argument is not a numeric value
#NUM! Occurs if the supplied number argument is less than 1

The ACOSH function returns the inverse hyperbolic cosine. The equation to calculate the inverse hyperbolic cosine is:


    \[    acosh(z) = ln \left( z + \sqrt{z+1} \sqrt{z-1} \right)    \]

See Wikipedia for more information on Inverse Hyperbolic Function.