1. When solving a trigonometric equation, the preliminary goal is to ________ the trigonometric function on one side of the equation.
2. The ________ solution of the equation 2 sin θ +1 = 0 is θ = 7π / 6 + 2nπ and θ = 11π / 6 + 2nπ, where n is an integer.
3. The equation 2 tan2 x − 3 tan x + 1 = 0 is a trigonometric equation of ________ type.
4. A solution of an equation that does not satisfy the original equation is an ________ solution.