Whats the difference between invoke, provoke and evoke?

The answers from Princeton:

Provoke:
# arouse: call forth (emotions, feelings, and responses); "arouse pity"; "raise a smile"; "evoke sympathy"

Evoke:
# arouse: call forth (emotions, feelings, and responses); "arouse pity"; "raise a smile"; "evoke sympathy"

Invoke:
# raise: summon into action or bring into existence, often as if by magic; "raise the specter of unemployment"; "he conjured wild birds in the air"; "call down the spirits from the mountain"
# appeal: request earnestly (something from somebody); ask for aid or protection; "appeal to somebody for help"; "Invoke God in times of trouble"

wordnet.princeton.edu/perl/webwn

apparently, evoke and provoke are synonymous while invoke carries a slightly different meaning.

Hello J:

An invoke is a voke with influence.. A provoke vokes for a living, and evoke is voking online.

excon

Both Provoke and Evoke are concerned with bringing about a response.
Provoking pushes for a response.
Evoking pulls the response from the other party.

Invoking has no counterpart. That which is invoked is merely called into being e.g invoking a ghostly spirit or invoking a state of national emergency.

Provoke tends to be a little more aggressive and explicit than evoke.
For example, one can provoke an attack from a wild animal, or provoke anger with harsh words.
Most commonly, it is used alone (e.g. "He provoked the dog") to bring about annoyance or anger.

Meanwhile, music can evoke a joyous feeling, or a homeless kitten's pitiful situation can evoke sympathy. Also, a photograph can evoke forgotten memories. Evoke is used in a more profound sense than provoke.

Invoke, on the other hand, is, in a sense, the most ethereal. Most commonly it means "to call upon" or "to bring about", as in to call upon a spirit or bring about inevitable death.