https://travis-ci.com/github/TheAlgorithms/Python/builds/166676400#L369

Travis tests have failed

Hey @zhbi98,
Please read the following log in order to understand the failure reason.
It'll be awesome if you fix what's wrong and commit the changes.

TravisBuddy Request Identifier: 0fbe89b0-abbf-11ea-a7dd-93c9ffbfb007

All of the trigonometric functions in the standard math library are in radians, which is why the tests are failing that try to compare sin() and _sin() (and other trig functions). Further more, even if we convert to radians, we will not get the exact same answer, due to float operations.

For example:

maths._sin(720)
7.153372857113005e-13
>>> math.sin(math.radians(720))
-4.898587196589413e-16

In your test for _power, you end up with 0 ** -100, which throws ZeroDivisionError: 0.0 cannot be raised to a negative power. However, there are larger issues with _power... You use range(n) to do repeat multiplication, but this will generate [] for a negative n, so any number raised to a negative n will return 1.

In general, for checking floats, you need to check against a tolerance instead of just using ==. For instance, math.sqrt(95) = 9.746794344808963 but maths._sqrt(95) = 9.746794344808965. These two values are not equal with ==, but are within 10^-14 of each other, which is often as good as you can do with floats.

https://docs.python.org/3/library/math.html#math.isclose