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find the maximum possible volume of a right circular cylinder if its total surface area including both ciruclar ends is 150pi

User Senerh
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1 Answer

4 votes

Final answer:

The maximum possible volume of a right circular cylinder with a total surface area of 150π can be found by maximizing the cubic function.

By taking the derivative of the volume formula with respect to r and solving for r, we can determine the value of r that yields the maximum volume.

Plugging this value of r back into the volume formula gives us the maximum possible volume: 250π cubic units.

Step-by-step explanation:

In this case, the total surface area is given as 150π.

We can substitute this value into the formula and solve for r or h by rearranging the equation.

Let's solve it for r:

150π = 2πr² + 2πrh

Divide both sides by 2π:

75 = r² + rh

We can express h in terms of r by rearranging the equation:

h = (75 - r²)/r

Now, substitute the value of h back into the volume formula:

V = πr²h

V = πr²[(75 - r²)/r]

Simplify the expression:

V = 75πr - πr³

To find the maximum volume, we need to find the maximum value of this cubic function.

To do this, we can take the derivative of V with respect to r and set it equal to zero:

dV/dr = 75π - 3πr²

= 0

Solve for r:

r² = 25

r = ±5

Since we are looking for the maximum volume, we take the positive value of r:

r = 5

Now, substitute this value of r back into the equation for h:

h = (75 - 25)/5

h = 10

Therefore, the maximum possible volume of the right circular cylinder is given by:

V = π(5)²(10)

= 250π cubic units

User Tom Ekberg
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