6.5 - 3 = 3.5
11 - 6.5 = 4.5
16.5 - 11 = 5.5
23 - 16.5 = 6.5
From this, you can see that the number being added is increasing by 1 each time.
Therefore, the pattern is adding 3.5, then 4.5, then 5.5, then 6.5, and so on.
The x-intercepts are indeed -1 and 1.
The increasing intervals are listed as (-1, 0) u (1, infinity) not because -1 and 1 are not included points of the function, but because the function is not differentiable in those points, so you can't tell whether the function is increasing or decreasing there.
If ir means not, then irrational means not rational. Pi is and irrational number.
Angles 5 and 6 are not congruent because they are on the same line, so the answer is I
