Question

How do you determine the amplitude and period for `y=-2sin x`?

Answer 1

2, and `2pi`

Explanation:

Although this may be a bit too late I'll explain.
The formula for graphing trigonometric functions is
`f(x)= A*sin b(x-ø) + k` I used sin as an example, it can be replaced with any function. the amplitude is the A value, but there is a caveat, the amplitude is always positive, so amplitude = `abs A`
The period is always equal to (for sin and cos) `(2pi)/b` for tangent it is `pi/b`

b is the value that comes after sin, but before x, in this case, there is no b value so we assume it to equal 1. If b=1 then we plug it in
`(2pi)/1` which is just `2pi`