Math Problem Statement

A cone-shaped paper drinking cup is to be made to hold 30 cm³ of water. Find the height and radius of the cup (in cm) that will use the smallest amount of paper. (Round your answers to two decimal places.)

Solution

It appears you have uploaded an image. I will now analyze its contents. Please give me a moment. PIL import Image

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image_path = '/mnt/data/1733688459346eju5o47x.jpg' img = Image.open(image_path)

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img.show()It seems that I can display the image, but I can't directly interpret the contents visually in this format. Let me extract text from the image (if any) to proceed with solving or explaining the mathematical problem. pytesseract

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extracted_text = pytesseract.image_to_string(img)

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extracted_textThe image contains the following math problem:

"A cone-shaped paper drinking cup is to be made to hold 30 cm³ of water. Find the height and radius of the cup (in cm) that will use the smallest amount of paper. (Round your answers to two decimal places.)"

To solve this problem, we need to find the height and radius of the cone that will minimize the surface area while holding a fixed volume of 30 cm³.

Here’s the approach:

Step 1: Write the volume and surface area equations.

  • The volume VV of a cone is given by: V=13πr2hV = \frac{1}{3} \pi r^2 h where rr is the radius and hh is the height.

  • The surface area AA of the cone is: A=πr2+πrr2+h2A = \pi r^2 + \pi r \sqrt{r^2 + h^2} where the first term is the area of the circular base, and the second term is the area of the slanted surface.

Step 2: Solve for the height in terms of the radius using the volume equation.

We are told the volume is 30 cm³, so: 30=13πr2h30 = \frac{1}{3} \pi r^2 h Solving for hh: h=90πr2h = \frac{90}{\pi r^2}

Step 3: Substitute into the surface area equation.

Substitute h=90πr2h = \frac{90}{\pi r^2} into the surface area formula: A(r)=πr2+πrr2+(90πr2)2A(r) = \pi r^2 + \pi r \sqrt{r^2 + \left( \frac{90}{\pi r^2} \right)^2}

Step 4: Minimize the surface area.

To minimize the surface area, we differentiate A(r)A(r) with respect to rr and set the derivative equal to zero. Solving this will give us the optimal value for rr, and from there, we can find hh.

Let me proceed with solving this. sympy import symbols, pi, sqrt, diff, solve

Define variables

r = symbols('r', positive=True)

Equation for the height in terms of r

h = 90 / (pi * r**2)

Surface area of the cone as a function of r

A = pi * r2 + pi * r * sqrt(r2 + h**2)

Differentiate the surface area function with respect to r

A_prime = diff(A, r)

Solve for critical points where the derivative is zero

critical_points = solve(A_prime, r)

critical_pointsThe critical point for minimizing the surface area occurs at a radius rr given by:

r=25/6451/32π1/3r = \frac{2^{5/6} \cdot 45^{1/3}}{2 \pi^{1/3}}

This expression involves constants and roots, so we can compute a numerical value for rr.

Let's calculate this radius and the corresponding height. Compute the numerical value for r r_value = (2**(5/6) * 45**(1/3)) / (2 * pi**(1/3))

Calculate the corresponding height h using the volume equation

h_value = 90 / (pi * r_value**2)

r_value, h_valueIt seems like I can’t do more advanced data analysis right now. Please try again later. If you’d like, I can help explain the general approach to solving the problem or guide you through the steps manually. Let me know how you'd like to proceed!

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Math Problem Analysis

Mathematical Concepts

Geometry
Optimization
Calculus

Formulas

Volume of a cone: V = (1/3)πr²h
Surface area of a cone: A = πr² + πr√(r² + h²)

Theorems

Optimization using derivatives
Critical points for minimum surface area

Suitable Grade Level

Grades 10-12