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33 lines
654 B
Plaintext
33 lines
654 B
Plaintext
NAME
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atanh - inverse hyperbolic tangent
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SYNOPSIS
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atanh(x [,eps])
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TYPES
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x real
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eps nonzero real, defaults to epsilon()
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return real
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DESCRIPTION
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Returns the atanh of x to a multiple of eps with error less in
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absolute value than .75 * eps.
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atanh(x) is the real number v for which tanh(v) = x. It is given by
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atanh(x) = ln((1 + x)/(1 - x))/2
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EXAMPLE
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> print atanh(.5,1e-5), atanh(.5,1e-10), atanh(.5,1e-15), atanh(.5,1e-20)
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.54931 .5493061443 .549306144334055 .5493061443340548457
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LIMITS
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none
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LIBRARY
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NUMBER *qatanh(NUMBER *x, NUMBER *eps)
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SEE ALSO
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asinh, acosh, asech, acsch, acoth, epsilon
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