document.write( "Question 1040188: Find the equation of the chord of the circle x^2+y^2-10x+9=0 which has midpoint (3,1) \n" ); document.write( "
Algebra.Com's Answer #654995 by Edwin McCravy(20077)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "We first get\r\n" );
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document.write( "x²+y²-10x+9 = 0\r\n" );
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document.write( "in standard form.\r\n" );
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document.write( "(x-5)²+(y-0)²=16\r\n" );
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document.write( "The center is (5,0) and the point (3,1) is the midpoint\r\n" );
document.write( "of the chord.\r\n" );
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document.write( "Draw in the two green radii and the red line from the \r\n" );
document.write( "center to the midpoint of the chord (3,1).\r\n" );
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document.write( "The two right triangles are congruent by SSS, so it's easy to\r\n" );
document.write( "prove that the red line is perpendicular to the chord.\r\n" );
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document.write( "So find the slope of the red line.\r\n" );
document.write( "Then the slope of the chord will be the negative reciprocal\r\n" );
document.write( "of the slope of the red line.\r\n" );
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document.write( "Then since the chord passes through (3,1), you will use\r\n" );
document.write( "the point-slope formula to get the equation of the chord.\r\n" );
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document.write( "If you have trouble, let me know in the thank-you note form \r\n" );
document.write( "below and I will get back to you by email.\r\n" );
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document.write( "Edwin
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