8 / VERSION 5A 4-27-77 PT
12 ASINEQ, FLDA FPI2AS /RETURN PI OVER TWO.
13 FMUL ASIN8 /TIMES ARG.
43 FLDA% BPASIN,1 /ADDR OF X
47 FSTA ASIN8 /STORE ARG AWAY.
48 JGE .+3 /TAKE ABSOLUTE VALUE.
50 FSUB F1ASIN /SEE IF >1
51 JLE ASINOK /CONTINUE PROCESS.
53 TRAP4 #ARGER /TRAP OUT.
55 ASINOK, FLDA ASIN8 /X USES STRAIGHT TRIG RELATION.
59 JEQ ASINEQ /IF 0,FAC=PI OVER 2
65 FSTA ASIN7 /SQRT(1.-X^2)
67 FDIV ASIN7 /X/SQRT(1.X^2)
70 JSR ATAN /TAKE THE ARCTANGENT.