<span>Answer: The derivative of 4pi (4π) is simply zero. In Calculus, the process of differentiation is taking the limit of the given as the change with respect to a certain variable approaches zero. The derivative indicates the slope of a given function, the rate of change with respect to small increments to a reference axis or variable. As our given, 4π, is simply a constant, it does not change with respect to any infinitesimal increment to any variable; thus its derivative is zero.</span>
Answer:

Step-by-step explanation:
Let x represents the number of nights Jack worked and y represents the number of nights Diane worked.
1. The number of nights Diane is scheduled to work is no more than four times the number of nights Jack is scheduled to play. Then

2. Diane will work at least 10 times before the concert. Then

3. Jack earns $50 per night that he plays, then he earned $50x in x nights. Diane earns $25 each night she works, then she earns $25y in y nigths. They need at least $750, so

4. We get the following set of constraints to model the problem:

(1,3)(3,5)
slope = (5-3) / (3-1) = 2/2 = 1
(3,5)(4,7)
slope = (7-5) / (4-3) = 2/1 = 2
False....they are not collinear because they have different slopes and do not lie on the same line
I believe the answer is y = -5/2x + 6