document.write( "Question 1181731: A sphere is inscribed in a right circular cone of altitude h and radius of base r. Write a formula in terms of r and h for the volume of the sphere. \n" ); document.write( "
Algebra.Com's Answer #850003 by ikleyn(52781)![]() ![]() You can put this solution on YOUR website! . \n" ); document.write( "A sphere is inscribed in a right circular cone of altitude h and radius of base r. \n" ); document.write( "Write a formula in terms of r and h for the volume of the sphere. \n" ); document.write( "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " After attentive reading the solution by @CPhill, I see the errors in it,\r \n" ); document.write( "\n" ); document.write( " that require me to fix them.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " So, I copy the solution by @CPhill and make my editing right there.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \r\n" ); document.write( "Here's how to derive the formula for the volume of the inscribed sphere in terms of *r* and *h*:\r\n" ); document.write( "\r\n" ); document.write( "**1. Diagram and Key Relationships:**\r\n" ); document.write( "\r\n" ); document.write( "Draw a cross-section of the cone and sphere. You'll see a circle (representing the sphere) inscribed in a triangle (representing the cone).\r\n" ); document.write( "\r\n" ); document.write( "* Let *R* be the radius of the inscribed sphere.\r\n" ); document.write( "* The radius of the cone's base is *r*.\r\n" ); document.write( "* The height (altitude) of the cone is *h*.\r\n" ); document.write( "* The slant height of the cone (the hypotenuse of the triangle) is *s* = sqrt(r² + h²).\r\n" ); document.write( "\r\n" ); document.write( "**2. Similar Triangles:**\r\n" ); document.write( "\r\n" ); document.write( "There are two similar right triangles in the cross-section:\r\n" ); document.write( "\r\n" ); document.write( "* The large triangle representing the cone, with sides *r*, *h*, and *s*.\r\n" ); document.write( "* A smaller triangle formed by the radius of the sphere (*R*), the difference between the cone's height and the sphere's radius (*h - R*), and a portion of the slant height.\r\n" ); document.write( "\r\n" ); document.write( "The ratio of corresponding sides in similar triangles is equal:\r\n" ); document.write( "\r\n" ); document.write( "R / r = (h - R) / s\r\n" ); document.write( "\r\n" ); document.write( "**3. Solve for R:**\r\n" ); document.write( "\r\n" ); document.write( "R / r = (h - R) / sqrt(r² + h²)\r\n" ); document.write( "R * sqrt(r² + h²) = r(h - R)\r\n" ); document.write( "R * sqrt(r² + h²) = rh - rR\r\n" ); document.write( "R * sqrt(r² + h²) + rR = rh\r\n" ); document.write( "R(sqrt(r² + h²) + r) = rh\r\n" ); document.write( "R = rh / (sqrt(r² + h²) + r)\r\n" ); document.write( "\r\n" ); document.write( "**4. Rationalize the Denominator (Optional but often preferred):**\r\n" ); document.write( "\r\n" ); document.write( "Multiply the numerator and denominator by the conjugate of the denominator:\r\n" ); document.write( "\r\n" ); document.write( "R = rh(sqrt(r² + h²) - r) / ((sqrt(r² + h²) + r)(sqrt(r² + h²) - r))\r\n" ); document.write( "\r\n" ); document.write( "R = rh(sqrt(r² + h²) - r) / (r² + h² - r²)\r\n" ); document.write( "\r\n" ); document.write( "R = rh(sqrt(r² + h²) - r) / h <<<---===\r \n" ); document.write( "\n" ); document.write( "Now everything is correct.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "In previous version by @CPhill, even the dimensions of the expressions were wrong.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "//////////////////////////////////////////\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " Regarding the post by @CPhill . . . \r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Keep in mind that @CPhill is a pseudonym for the Google artificial intelligence.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The artificial intelligence is like a baby now. It is in the experimental stage \n" ); document.write( "of development and can make mistakes and produce nonsense without any embarrassment.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " It has no feeling of shame - it is shameless.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "This time, again, it made an error.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Although the @CPhill' solution are copy-paste Google AI solutions, there is one essential difference.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Every time, Google AI makes a note at the end of its solutions that Google AI is experimental \n" ); document.write( "and can make errors/mistakes.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "All @CPhill' solutions are copy-paste of Google AI solutions, with one difference: \n" ); document.write( "@PChill never makes this notice and never says that his solutions are copy-paste that of Google.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Every time, @CPhill embarrasses to tell the truth.\r \n" ); document.write( "\n" ); document.write( "But I am not embarrassing to tell the truth, as it is my duty at this forum.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "And the last my comment.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "When you obtain such posts from @CPhill, remember, that NOBODY is responsible for their correctness, \n" ); document.write( "until the specialists and experts will check and confirm their correctness.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Without it, their reliability is ZERO and their creadability is ZERO, too.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Dear @CPhill, I will include such comment to every your post, where I will find an error,\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "UNTIL you will place a correct acknowledgment in every your post.\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |