can i choose to tap vigilance creature when attacking

[Nik]

if i attack with vigilance creature can I decide not to use its vigilant ability and tap it anyway as its attacking?

[Arix]

No, vigilance isn't optional.

[Neloj]

Yah... Ryt...

But,, isn't it,, the rulings about the 'vigilance'... Is

''attacking of this creature cant cause to tap..''..?

Now,,(here's my question)

can i attack a creature with vigilance that is already tapped..??

[Arix]

No. Vigilance stops an attacking creature from tapping, but it still needs to be untapped in order to be declared as an attacker in the first place.