<u>Answer:</u>

<u>Step-by-step explanation:</u>
We know from the question that the student earned $12.50 <em>per hour</em>.
Using this information, we can say that if the student worked for <em>h </em>hours, they would make a total of 12.50 × <em>h </em>dollars.
We also know that the total money they earned is $2500.75.
∴ Therefore, we can set up the following equation:

From here, if we want to, we can find the number of hours worked by simply making <em>h</em> the subject of the equation and evaluating:
<em>h </em>=<em> </em>
= 200.6 hours
The answer is possibly 10
Domain are all the possible x values of a function. When you look at a cosine graph you can see that it goes on into infinity in the x or horizontal direction. This means that all x values are included in cosine. Because of this the domain is:
all real numbers
or
(-∞,∞)
^^^ It can be written both ways
Hope this helped! Let me know if there is anything else I can do!