What does it really mean for something to be "trivial"? I see this word a lot when I read about mathematics. Is this meant to be another way of saying "obvious" or "easy"? What if it's actually wrong? It's like when I see "the rest is left as an exercise to the reader", it feels like a bit of a cop-out. What does this all really mean in the math communities? 

Trivial
A solution or example that is ridiculously simple and of little interest. Often, solutions or examples involving the number 0 are considered trivial. Nonzero solutions or examples are considered nontrivial.
For example, the equation x + 5y = 0 has the trivial solution x = 0, y = 0. Nontrivial solutions include x = 5, y = –1 and x = –2, y = 0.4.
P.S : i got those explanation from here .
