Using the sinusoidal function, it is found that the temperature will be below 0ºC between May and August.
<h3>What is a Sinusoidal function?</h3>- A sinusoidal function is a function that depends on a trigonometric function, having peaks according to the period and amplitude given by this function.
The function for the average monthly temperature, in m months after January, is given by:
Working with elementary angles, we have that:
From this, we have that it becomes negative after March, and positive before September, removing the middle two options.
Now, we have to test for April and May, that is, m = 4 and m = 5, hence:
Negative only in May, hence the temperature will be below 0ºC between May and August.
To learn more about sinusoidal function, you can take a look at brainly.com/question/18055768