Er, I meant that x at the interval (0,1) and (1,3) and (3,4), not x at the coordinates 0,1 etc. Usually we write that x is an element of (0,1), meaning x on the interval between 0 and 1, <b>exclusive</b>. x being an element of [0,1] means that x is on the interval 0 and 1, <b>inclusive</b>. Another way of writing x as an element of [0,1] is 0 <u><</u> x <u><</u> 1 and x as an element of (0,1) is 0 < x < 1. If you look on your graph during these intervals, you’ll see that the slope is slanted upwards.

edit: Are you sure number 6 is phrased like that? It doesn’t really make any sense right now…