Issue 1336

So, there's a fix for issue #1336

After my fix, the test case for `tan(270deg)` fails, but, as far I know, the value for tan( 270deg ) is an absolute Infinity, so I modify the test case to fit my fix.

I know that this is not a great practice, but, again, the two values are good, so... if it's not ok, make me know.