Answer:
(2) (100, 300)
Step-by-step explanation:
One wave can be divided on 4 parts, as show on the picture.
Since a length of one whole wave equals 400, a length of each part is [tex]400:4=100[/tex] nanometers.
The height of the wave is decreasing on the second and on the third part, hence over the interval (100, 300).