cos isn't always the same ratio with the same degrees
I just wanted to calculate: cos(89.853) (rounded to 10 dez. , webversion) the result was -0.3122963958 that doesn't make sense. Then I openened geogebra in a new Tab and i got the right result. But that isn't acceptable that geogebra calculates wrong sometimes that's at least the third time something like that happened.