The math.acosh() function returns the inverse hyperbolic cosine of a number.

math.acosh(x)

Where, x is a number which must be greater than or equal to 1.

The function returns the inverse hyperbolic cosine of x, which is a number between 0 and pi. 

import math

print(math.acosh(3))

print(math.acosh(7))
print(math.acosh(52))

This function is useful for calculating angles and distances in trigonometry problems.