BBC BASIC Programmers' Reference

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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