document.write( "Question 1039233: Find the equation of the circle which touches the X axis at the point (3,0) and cuts off an intercept 8 units from the positive part of the y axis \n" ); document.write( "
Algebra.Com's Answer #653976 by Edwin McCravy(20054)\"\" \"About 
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Find the equation of the circle which touches the X axis at the point (3,0) and cuts off an intercept 8 units from the positive part of the y axis\r
\n" ); document.write( "\n" ); document.write( "The standard equation of any circle is\r
\n" ); document.write( "\n" ); document.write( "\"%28x-h%29%5E2%2B%28y-k%29%5E2=r%5E2\"\r
\n" ); document.write( "\n" ); document.write( "Since it is tangent to the x-axis at (3,0),
\n" ); document.write( "the center is directly above (3,0), so its
\n" ); document.write( "center also has x-coordinate 3. So h=3\r
\n" ); document.write( "\n" ); document.write( "\"%28x-3%29%5E2%2B%28y-k%29%5E2=r%5E2\"\r
\n" ); document.write( "\n" ); document.write( "It passes through (x,y) = (3,0), so\r
\n" ); document.write( "\n" ); document.write( "\"%283-3%29%5E2%2B%280-k%29%5E2=r%5E2\"\r
\n" ); document.write( "\n" ); document.write( "\"0%5E2%2Bk%5E2=r%5E2\"\r
\n" ); document.write( "\n" ); document.write( "\"k%5E2=r%5E2\"\r
\n" ); document.write( "\n" ); document.write( "k and r are both positive numbers.\r
\n" ); document.write( "\n" ); document.write( "\"k=r\" and\r
\n" ); document.write( "\n" ); document.write( "\"%28x-3%29%5E2%2B%28y-r%29%5E2=r%5E2\"\r
\n" ); document.write( "\n" ); document.write( "It has a y-intercept at (0,8)\r
\n" ); document.write( "\n" ); document.write( "\"%280-3%29%5E2%2B%288-r%29%5E2=r%5E2\"\r
\n" ); document.write( "\n" ); document.write( "\"%28-3%29%5E2%2B64-16r%2Br%5E2=r%5E2\"\r
\n" ); document.write( "\n" ); document.write( "\"9%2B64-16r%2Br%5E2=r%5E2\"\r
\n" ); document.write( "\n" ); document.write( "\"73-16r=0\"\r
\n" ); document.write( "\n" ); document.write( "\"-16r=-73\"\r
\n" ); document.write( "\n" ); document.write( "\"r=%28-73%29%2F%28-16%29\"\r
\n" ); document.write( "\n" ); document.write( "\"r=73%2F16\"\r
\n" ); document.write( "\n" ); document.write( "And since \"x=r=73%2F16\",\r
\n" ); document.write( "\n" ); document.write( "\"%28x-3%29%5E2%2B%28y-73%2F16%29%5E2=%2873%2F16%29%5E2\"\r
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