C, always go with supervisors
Answer:
The dimensions of the can that will minimize the cost are a Radius of 3.17cm and a Height of 12.67cm.
Step-by-step explanation:
Volume of the Cylinder=400 cm³
Volume of a Cylinder=πr²h
Therefore: πr²h=400

Total Surface Area of a Cylinder=2πr²+2πrh
Cost of the materials for the Top and Bottom=0.06 cents per square centimeter
Cost of the materials for the sides=0.03 cents per square centimeter
Cost of the Cylinder=0.06(2πr²)+0.03(2πrh)
C=0.12πr²+0.06πrh
Recall: 
Therefore:



The minimum cost occurs when the derivative of the Cost =0.






r=3.17 cm
Recall that:


h=12.67cm
The dimensions of the can that will minimize the cost are a Radius of 3.17cm and a Height of 12.67cm.
First step is to simplify the equation so that it makes our life easier! Since 2^2 is equivalent to 4, we can plug that into the equation. Then we can also simplify 2^4 to 16. Now it should look like this:
(4)(2)/16
Now we can solve. 4(2) = 8 so now we have 8/16. 8/16 simplifies to 1/8 when you divide the numerator and the denominator by 8. So there you go! Your final answer is 1/8! I really hope that helped you out, and happy holidays!
It would take 21gal to cover 7 flowerbeds. Hope this helps! :D