Problem 2 A salesperson's monthly salary is related to the amount of sales she generates in the following way. She receives a basic amount of $500, even if she sells nothing. On the first $10,000 of monthly sales, she earns a commission of 10%. Furthermore, she earns a commission of 20% on the portion of sales that falls between $10,000 and $20,000. Finally, she earns a commission of 25 cents on every dollar of sales she generates in excess of $20,000. (a) Compute the salesperson's salary for a month in which she has generated $35,000 of sales. (b) Graph the function relating the salesperson's pay to the amount of sales she man- ages. (c) Is this function continuous? (d) Are there any points at which this function is not differentiable