Converting Angle to X and Y Values: 90/180/270 deg

[qrani]

So I have a way to turn an angle into x and y values:

angle = math.radians(0)
y = math.cos(angle)
x = math.sin(angle)
print(x,y)

and it prints:

Output:
0.0 1.0

but then, I change they 0 to 90:

angle = math.radians(90)
y = math.cos(angle)
x = math.sin(angle)
print(x,y)

and would expect to have 1.0 0.0 as the output, but got this:

Output:
1.0 6.123233995736766e-17

which is a super miniscule number, but why isn't it 1.0 0.0?
and how can I make it right?

[woooee]

http://docs.python.org/tutorial/floatingpoint.html or
http://www.lahey.com/float.htm

how can I make it right?

Use Python's decimal module for more precision than a floating point.