Hyperbolic version of Napier’s mnemonic

I was looking through an old geometry book [1] and saw a hyperbolic analog of Napier's mnemonic for spherical trigonometry. In hindsight of course there's a hyperbolic analog: there's a hyperbolic analog of everything. But I was surprised because I'd never thought of this before. I suppose the spherical version is famous because of its practical use in navigational calculations, while the hyperbolic analog is of more theoretical interest.

Napier's mnemonic is a clever way to remember 10 equations in spherical trig. See the linked post for the meanings of the variables.

sina= sinAsinc= tanbcotB
sinb= sinBsinc= tanacotA
cosA= cosasin B = tanbcotc
cosB= cosbsin A = tanacotc
cosc= cotAcotB= cosacosb

The hyperbolic analog replaces every circular function ofa,b, orc with its hyperbolic counterpart.

sinh a= sinA sinhc = tanhbcotB
sinh b= sinB sinhc = tanhacotA
cosA = cosha sin B = tanhb cothc
cosB = coshb sin A = tanha cothc
cosh c= cotAcotB = cosha coshb

[1] D. M. Y. Sommerville. The Elements of Non-Euclidean Geometry. 1919.

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