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REAL FUNCTION COSH (X) C$ (Hyperbolic Cosine) C$ Return the hyperbolic cosine of the REAL argument X. C$ C$ The host exponential function is used for the computation, C$ with precautions taken to prevent premature overflow for C$ large abs(X). C$ C$ The ELEFUNT tests of W.J. Cody, Jr. and W. Waite, C$ "Software Manual for the Elementary Functions", C$ Prentice-Hall, Englewood Cliffs, NJ, USA (1980) have been C$ made on the DEC-20/60, with the following results: C$ C$ abs(x) in 0 .. 1/2 - maximum relative error: 1.00 bits lost C$ - RMS relative error: 0.00 bits lost C$ abs(x) in 3 .. 88.03 - maximum relative error: 2.53 bits lost C$ - RMS relative error: 0.68 bits lost C$ (04-SEP-82)