BBC BASIC Programmers' Reference

by Richard Russell, April 2018

Liberty BASIC doesn't include the hyperbolic trig functions (sinh, cosh, tanh etc.) as a built-in feature, but they can easily be synthesised as user-defined functions as follows:

function sinh(x)
    sinh = (exp(x) - exp(-x)) / 2
end function
 
function cosh(x)
    cosh = (exp(x) + exp(-x)) / 2
end function
 
function tanh(x)
    tanh = (exp(x) - exp(-x)) / (exp(x) + exp(-x))
end function
 
function coth(x)
    coth = (exp(x) + exp(-x)) / (exp(x) - exp(-x))
end function
 
function sech(x)
    sech = 2 / (exp(x) + exp(-x))
end function
 
function csch(x)
    csch = 2 / (exp(x) - exp(-x))
end function