Axiom, 266 215 210 bytes
g(y,a,b)==(r:List Float:=[];t:=y+truncate((a-y)/360)*360;repeat(t>b=>break;if t>=a then r:=append(r,[t]);t:=t+360);r)
f(x,a,b)==(abs(x)>1 or a>b=>[];y:=asin(x)*180/%pi;z:=180-y;sort(append(g(y,a,b),g(z,a,b))))
ungolf and test
-- g/180=r/pi => r=pi*g/180
--y+k*360=a
-- a-y
-- k=------
-- 360
-- find all angles of the same class of angles [y+k*360] in interval [a,b]
gg(y,a,b)==
r:List Float:=[]
t:=y+truncate((a-y)/360)*360 --truncate(1.9)=1, truncate(-3.1)=-4 is ok
repeat
t>b=>break
if t>=a then r:=append(r,[t])
t:=t+360
r
-- ff returns the list of solution y of sin(y)=x with y in the interval [a,b]
ff(x,a,b)==
abs(x)>1 or a>b =>[]
y:=asin(x)*180/%pi -- z and y are the only 2 solutions in one 360 Len interval
z:=180-y
sort(append(gg(y,a,b),gg(z,a,b)))
(6) -> f(0.5, 0, 360)
(6) [30.0,150.0]
Type: List Float
(7) -> f(-0.2, 56, 243)
(7) [191.5369590328 1548769]
Type: List Float
(8) -> f(0.0, -1080, 1080)
(8)
[- 1080.0, - 900.0, - 720.0, - 540.0, - 360.0, - 180.0, 0.0, 180.0, 360.0,
540.0, 720.0, 900.0, 1080.0]
(14) -> m:=f(-0.1, -2035, -243)
(14)
[- 1974.2608295227 33214, - 1805.7391704772 66786, - 1614.2608295227 33214,
- 1445.7391704772 66786, - 1254.2608295227 33214, - 1085.7391704772 66786,
- 894.2608295227 332137, - 725.7391704772 667863, - 534.2608295227 332137,
- 365.7391704772 667863]
Type: List Float
(15) -> map(x+->sin(%pi*x/180), m)
(15)
[- 0.0999999999 9999999987, - 0.1000000000 0000000016,
- 0.0999999999 9999999986 2, - 0.1000000000 0000000028,
- 0.0999999999 9999999985 4, - 0.1000000000 0000000018,
- 0.0999999999 999999999, - 0.1000000000 0000000019,
- 0.0999999999 9999999989 2, - 0.1000000000 0000000014]
Type: List Float