Mitsubishi QD51 Programming Manual page 668

APPENDIX
Appendix 5 How to Obtain Trigonometric Functions not Available in AD51H-BASIC
Derived function
Arc sine
Arc cosine
Arc secant
Arc cosecant
Arc cotangent
Cosecant
Cotangent
Secant
Hyperbolic sine
Hyperbolic cosine
Hyperbolic tangent
Hyperbolic secant
Hyperbolic cosecant
Hyperbolic cotangent
Hyperbolic arc sine
Hyperbolic arc cosine
Hyperbolic arc tangent
Hyperbolic arc secant
Hyperbolic arc cosecant
Hyperbolic arc cotangent
Note that a certain degree of inaccuracy may occur.
App - 23
A trigonometric function not available in AD51H-BASIC can be derived by combining
existing trigonometric functions.
The table below shows formulas for the derived trigonometric functions.
ARCSIN(X)=ATN(X/SQR(–X X+1))
ARCCOS(X)=–ATN(X/SQR(–X X+1))+1.5708
ARCSEC(X)=ATN(SQR(X X–1))+(SGN(X)–1) 1.5708
ARCCSC(X)=ATN(1/SQR(X X–1))+(SGN(X)–1)
ARCCOT(X)=–ATN(X)+1.5708
SCS(X)=1/SIN(X)
COT(X)=1/TAN(X)
SEC(X)=1/COS(X)
SINH(X)=(EXP(X)–EXP(–X))/2
COSH(X)=(EXP(X)+EXP(–X))/2
TANH(X)=–EXP(–X)/(EXP(X)+EXP(–X))
SECH(H)=2/(EXP(X)+EXP(–X))
CSCH(H)=2/(EXP(X)-EXP(–X))
COTH(X)=EXP(–X)/(EXP(X)–EXP(–X)) 2+1
ARCSINH(X)=LOG(X+SCR(X X+1))
ARCCOSH(X)=LOG(X+SQR(X X–1))
ARCTANH(X)=LOG((1+X)/(1–X))/2
ARCSECH(X)=LOG((SQR(–X X+1)+1)/X)
ARCCSCH(X)=LOG((SGN(X)
ARCCOTH(X)=LOG((X+1)/)X–1))/2
MELSEC-Q
Expression
2+1
SQR(X X+1)+1)/X)
1.5708
App - 23