Here, `b = 8`, so the period is `(2π)/8 = π/4.` To draw 2 cycles, we will need to graph from `0` to ` π/2` along the x-axis.
The graph of `y=3cos(8x)` for `0 ≤ x ≤ pi/2`
Note that we started the graph at `x = 0`, but we could have started anywhere. As long as we draw exactly 2 cycles, we are answering the question.
Now for interest, let's see what it looks like from `0` to 2π.
The graph of `y=3cos(8x)` for `0 ≤ x ≤ 2pi`
Note that there are 8 cycles between `0` and 2π.