Radio Shack TRS-80 User Manual page 221

ArcCosine
Computes: Arccos(S), angle
whose
cosine
is
S
Input:
S,0«=SO=1
Output:
Yin
degrees,
Wi$
in
mdians
Also
uses:
X,Z
internally
Other
subroutines required:
ArcSine
How
to
call:
GOSUB
30500
33000 END
30500 REM *ARCC05* INPUT
5,
OUTPUT
Y,W
30510 REM
Y
IS IN DEGREES,
W
IS
IN
RADIANS
30520
GOS.
30550
:
Y=90-Y
:
W =
1.570796-W
:
RET.
ArcSine
Computes:
ArcSin(S), angle
whose
sine
is
S
:lriput;:.Sv0<=S<=l:.
Output;
Yin
degrees,
Win
racEi^»
Also
uses:
X,Y
internally
Other
subroutines required:
None
How
to call:
30550
30000 END
30530 REM *ARCSIN SUBROUTINE* INPUT
S,
OUTPUT Y,W
30535 REM
Y IS IN
DEGREES,
W
IS IN
RADIANS
30540 REM ALSO USES VARIABLES
X,Z INTERNALLY
305S0
X = S
i
IF
ABSt
S
)<=
.
707107
T.
30610
30560 X=1-S*S
i
IF
X<0
T. P. Si
"IS OUT
OF
RANGE"
:
STOP
30570 W=X/2
t
Z=0
30580 Y=(X/W-W>/2
:
IF <Y=0)+{Y=Z)
T.
X = W
:
G.
30610
30600 W=W+Y
i
Z=Y
G.
30580
30610 Y=X+X*X*X/6+X*X*X*X*X*
.
075
+ X
+ X*X
*X*X*X*X*
4
.
464286
E-
2
30620 W=Y+X*X*X*X*X*X*X*X*X*3.038194E-2
30625
IF
ABS( S)>. 707107
T.
W=1.570796-W
30630 Y=W*57. 29578
:
RET.
ArcTangent
Computes: ATN{X),
angle
whose tangent
is
X
Input:
x
.O^ut;
v
;^ :
|n
;
;de^.e3j'A :
:in''ricnans
Also
uses:
B,T
internally.
Value
of
X
is
changed.
Other
subroutines
required: Sign
How
to
call:
GOSUB
30690
30000 END
30660 REM *ARCTANGENT*
INPUT X, OUTPUT
C
,
A
30670 REM
C
IS IN
DEGREES.
A
IS IN
RADIANS
306B0 REM ALSO USES B,T INTERNALLY
30690 GOS. 30810
:
X=AB5(X)
:
C=0
30700
IF
X>1
T.
C=l
:
X=l/X
30710 A=X*X
30
7 20 B=t
(
2
.86 62
3E-3*A-1 .61657E-2
)*A + 4
.
2909 6E-2
>*A
30
7
30 B=(
( (
(B-7.5289E-2)*A+. 106563)* A-
,
14
2089
)
*A+.
19 99
36)*A
30740 A=( (B-
.
333332 )*A+1)*X
30750
IF C=l T.
A=1.570796-A
30760
A
=
T*A
j
C=A*57. 29578
:
RET.
219