The exercise description says:

"Solve the inequality. Express the exact answer in interval notation, restricting your attention to -PI <= x <= PI.

Exercise 84. sin^2(x)<3/4

The answer says: (-2PI/3,-PI/3)U(PI/3,2PI/3)

but it seems not to be correct (see the graph):

So I would expect the answer to be: [-PI, -2PI/3)U(-PI/3, PI/3)U(2PI/3, PI].

Or maybe I'm missing something. I'm referring to the 3rd edition of the book.

Regards

Adam