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33 lines
707 B
Plaintext
33 lines
707 B
Plaintext
NAME
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acosh - inverse hyperbolic cosine
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SYNOPSIS
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acosh(x [,eps])
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TYPES
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x real, x >= 1
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eps nonzero real, defaults to epsilon()
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return nonnegative real
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DESCRIPTION
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Returns the cosh of x to a multiple of eps with error less in
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absolute value than .75 * eps.
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acosh(x) = ln(x + sqrt(x^2 - 1)) is the nonnegative real number v
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for which cosh(v) = x.
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EXAMPLE
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> print acosh(2, 1e-5), acosh(2, 1e-10), acosh(2, 1e-15), acosh(2, 1e-20)
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1.31696 1.3169578969 1.316957896924817 1.31695789692481670862
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LIMITS
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unlike sin and cos, x must be real
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eps > 0
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LIBRARY
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NUMBER *qacosh(NUMBER *x, NUMBER *eps)
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SEE ALSO
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asinh, atanh, asech, acsch, acoth, epsilon
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