document.write( "Question 1198563: The bases of a frustum of a right circular cone are circles whose diameters are respectively 18 and 14 inches. With a slant height of 25 inches, the volume may be expressed as V = Χπ √γ in^3 where Χ and γ are integers. Find the smallest sum of Χ and γ. \n" ); document.write( "
Algebra.Com's Answer #848324 by CPhill(1959)![]() ![]() You can put this solution on YOUR website! \r \n" ); document.write( "\n" ); document.write( "Certainly, let's find the volume of the frustum and determine the smallest sum of Χ and γ.\r \n" ); document.write( "\n" ); document.write( "**1. Find the radii of the bases:**\r \n" ); document.write( "\n" ); document.write( "* Radius of the larger base (R): 18 inches / 2 = 9 inches \n" ); document.write( "* Radius of the smaller base (r): 14 inches / 2 = 7 inches\r \n" ); document.write( "\n" ); document.write( "**2. Find the height (h) of the frustum:**\r \n" ); document.write( "\n" ); document.write( "* We can use the Pythagorean theorem with the slant height (l = 25 inches), the radius difference (R - r = 2 inches), and the height (h):\r \n" ); document.write( "\n" ); document.write( " l² = (R - r)² + h² \n" ); document.write( " 25² = 2² + h² \n" ); document.write( " h² = 625 - 4 \n" ); document.write( " h² = 621 \n" ); document.write( " h = √621 inches\r \n" ); document.write( "\n" ); document.write( "**3. Calculate the volume (V) of the frustum:**\r \n" ); document.write( "\n" ); document.write( "* The formula for the volume of a frustum of a right circular cone is:\r \n" ); document.write( "\n" ); document.write( " V = (1/3) * π * h * (R² + Rr + r²) \r \n" ); document.write( "\n" ); document.write( "* Substitute the values:\r \n" ); document.write( "\n" ); document.write( " V = (1/3) * π * √621 * (9² + 9*7 + 7²) \n" ); document.write( " V = (1/3) * π * √621 * (81 + 63 + 49) \n" ); document.write( " V = (1/3) * π * √621 * 193\r \n" ); document.write( "\n" ); document.write( "**4. Express the volume in the form V = Χπ√γ**\r \n" ); document.write( "\n" ); document.write( "* V = (1/3) * π * √621 * 193 \n" ); document.write( "* V = (193/3) * π * √621\r \n" ); document.write( "\n" ); document.write( "* Therefore: \n" ); document.write( " * Χ = 193 \n" ); document.write( " * γ = 621\r \n" ); document.write( "\n" ); document.write( "**5. Find the smallest sum of Χ and γ**\r \n" ); document.write( "\n" ); document.write( "* Χ + γ = 193 + 621 = 814\r \n" ); document.write( "\n" ); document.write( "**Therefore, the smallest sum of Χ and γ is 814.** \n" ); document.write( "**1. Find the Radii**\r \n" ); document.write( "\n" ); document.write( "* **Radius of the larger base:** 18 inches / 2 = 9 inches \n" ); document.write( "* **Radius of the smaller base:** 14 inches / 2 = 7 inches\r \n" ); document.write( "\n" ); document.write( "**2. Find the Height of the Frustum**\r \n" ); document.write( "\n" ); document.write( "* Let 'h' be the height of the frustum. \n" ); document.write( "* We can use the Pythagorean theorem with the slant height and the difference in radii to find the height.\r \n" ); document.write( "\n" ); document.write( "* Consider a right triangle formed by: \n" ); document.write( " * The base: Difference in radii = 9 inches - 7 inches = 2 inches \n" ); document.write( " * The height: 'h' \n" ); document.write( " * The hypotenuse: Slant height = 25 inches\r \n" ); document.write( "\n" ); document.write( "* Using Pythagorean Theorem: \n" ); document.write( " * h² = 25² - 2² \n" ); document.write( " * h² = 625 - 4 \n" ); document.write( " * h² = 621 \n" ); document.write( " * h = √621 inches\r \n" ); document.write( "\n" ); document.write( "**3. Find the Volume of the Frustum**\r \n" ); document.write( "\n" ); document.write( "* The formula for the volume (V) of a frustum of a right circular cone is:\r \n" ); document.write( "\n" ); document.write( " V = (1/3) * π * h * (R² + Rr + r²) \r \n" ); document.write( "\n" ); document.write( " where: \n" ); document.write( " * h is the height of the frustum \n" ); document.write( " * R is the radius of the larger base (9 inches) \n" ); document.write( " * r is the radius of the smaller base (7 inches)\r \n" ); document.write( "\n" ); document.write( "* V = (1/3) * π * √621 * (9² + 9*7 + 7²) \n" ); document.write( "* V = (1/3) * π * √621 * (81 + 63 + 49) \n" ); document.write( "* V = (1/3) * π * √621 * 193\r \n" ); document.write( "\n" ); document.write( "**4. Express the Volume in the Form V = Χπ√γ**\r \n" ); document.write( "\n" ); document.write( "* V = (193/3) * π * √621 \r \n" ); document.write( "\n" ); document.write( "* **Therefore:** \n" ); document.write( " * Χ = 193/3 \n" ); document.write( " * γ = 621\r \n" ); document.write( "\n" ); document.write( "**5. Find the Smallest Sum of Χ and γ**\r \n" ); document.write( "\n" ); document.write( "* Sum = Χ + γ = (193/3) + 621 \n" ); document.write( "* Sum = (193 + 1863)/3 \n" ); document.write( "* Sum = 2056/3 \r \n" ); document.write( "\n" ); document.write( "**Therefore, the smallest sum of Χ and γ is 2056/3.** \n" ); document.write( " \n" ); document.write( " |