# TI-BASIC:Arcosh

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Jump to navigationJump to search**Command Summary**

Calculates the inverse hyperbolic cosine of a value.

**Command Syntax**

coshֿ¹(*value*)

**Menu Location**

The coshֿ¹( command can only be found in the catalog. Press:

- 2nd CATALOG to access the command catalog.
- C to skip to commands starting with C.
- Scroll down and select coshֿ¹(

TI-83/84/+/SE

1 byte

The coshֿ¹( function gives the inverse hyperbolic cosine of a value. coshֿ¹(x) is the number y such that x = cosh(y).

Although coshֿ¹(x) can be defined for all real and complex numbers, it assumes real values only for x≥1. Since hyperbolic functions in the Z80 calculators are restricted only to real values, ERR:DOMAIN is thrown when x<1.

The coshֿ¹( command also works for lists.

coshֿ¹(1) 0 coshֿ¹({2,3}) {1.316957897 1.762747174}

# Error Conditions

**ERR:DOMAIN**when taking the inverse cosh of a number less than 1.