Tutorial P2_03

Hello people
I have a problem with the tutorial P2_03.
I want to draw the display with the same data but with
the points connected to lines.
What parts exactly do i have to change to get
the display with lines without changing
float[][] point_vals = new float[][]{{-3.0f, -1.5f, 0.0f, 1.5f, 3.0f,},
{0.0f, 33.75f, 45.0f, 33.75f, 0.0f,} };.

thanks everyone