How do you graph y=-3/2sinx over 0<=x<=360?

1 Answer
May 20, 2018

See below.

Explanation:

Let's see how the function we want to study is obtain from the standard sine function, and how these transformation reflect on the graph:

  • First of all, I assume you are familiar with the graph of the standard sine function:
    graph{sin(x) [-0, 6.28, -1.5, 1.5]}
  • Then we must switch sign. The transformation f(x) -> -f(x) affects the graph by vertical symmetry (we reflect with respect to the x axis:
    graph{-sin(x) [-0, 6.28, -1.5, 1.5]}
  • Finally, we multiply the function by a constant: the transformation f(x) \to kf(x) results in a vertical stretch if k>1, or a vertical compression otherwise. In our case, we're stretching the graph by a factor 1.5. Note how the new maximum and minimum is not 1 anymore but 1.5
    standard sine function:
    graph{-1.5*sin(x) [-0, 6.28, -2, 2]}