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Question
junior college 1 | H2 Maths
2 Answers Below
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Im confused
Date Posted: 7 years ago
Views: 605
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Sorry if my handwriting is shit or i made some calculation mistakes as i did it in a rush. But the train of thought is there. Please follow the red color lines as well as the working to understand my train of thought about this question.
Date Posted:
7 years ago
The steps and workings are correct, but I feel that logically speaking the container should have a circular base so I recommend you include that in your total surface area.
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I assumed the bottom of the cylinder is closed. Since Volume is already given, express h in terms of r so that it can be substituted into the Area (A) equation. The question is asking for least surface area, so the differential equation we need to find will be dA / dr. After eqauting dA/dr =0,we can find r and check if the value of r gives us the minimum surface area. From there, you can multiply the Area with the cost to find the minimum surface area cost.
(my r looks like a v so I apologise for that!)
(my r looks like a v so I apologise for that!)
Date Posted:
7 years ago
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