OB = 1
BA is a straight line perpendicular to OB
y-length of the segment BA is measured relative to O
The Sine at O equals the hyperbolic sin of the y-length divided
by the hyperbolic cosine of the y-length
The Cosine at O equals the reciprocal of the hyperbolic cosine of the
y-length.
The Tangent at O equals the hyperbolic sin of the y-length.
Sin O = sinh [y-length] / cosh [y-length]
Cos O = cosh-1 [y-length]
Tan O = sinh [y-length]
in the diagram:
AB = 1.959592
AO = 2.2
Tan O = (e1.425417 - e-1.425417) / 2
= (4.159592 - .240408) / 2
= 1.95959
Cos O = 1 / [(e1.425417 + e-1.425417)] / 2
1 / (4.159592 + .240408)/2
= .45455