Answer:
a) Y(x) = {900, x≤30; 900-40(x-30), x>30}
b) T(x) = {900x, x≤30; 2100x-40x², x>30}
c) dT/dx = {900, x≤30; 2100-80x, x>30}
Step-by-step explanation:
a) The problem statement gives the function for x ≤ 30, and gives an example of evaluating the function for x = 35. So, replacing 35 in the example with x gives the function definition for x > 30.

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b) The yield per acre is the product of the number of trees and the yield per tree:
T(x) = x·Y(x)

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c) The derivative is ...

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The attached graph shows the yield per acre (purple, overlaid by red for x<30), the total yield (black), and the derivative of the total yield (red). You will note the discontinuity in the derivative at x=30, where adding one more tree per acre suddenly makes the rate of change of yield be negative.
You would use the counting principal. 12X3X3
Answer:
work it out it is so easy
Step-by-step explanation:
Answer:
The distance of the playground is 540m
Step-by-step explanation:
Here, we are interested in calculating the length of the playground given the information in the question.
Where to attack the question from is the segment that states that he took a break after 480m and also had 2 breaks. Thus, the distance traveled would be 480 * 2 = 960 m
Now, to find the length of the track, we add the distance covered plus the distance uncovered. Mathematically that would be 960m + 120m = 1,080m
In the last part of the question, we are told that the track is twice as long as the playground. This means that the length of the playground or the distance of the playground is 1080/2 = 540 m
0.8
you find how much he needed so:
24*0.3=7.2
than 8 he had , so whats left over
8-7.2=0.8