document.write( "Question 746357: How do I write an equation for a circle whose center is (3,-1) and radius is 2? \n" ); document.write( "
Algebra.Com's Answer #454233 by Edwin McCravy(20059)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "You must memorize the standard equation of a circle \r\n" );
document.write( "with center = (h,k) and radius = r\r\n" );
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document.write( "(x - h)² + (y - k)² = r²\r\n" );
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document.write( "In your problem center = (h,k) = (3,-1) and \r\n" );
document.write( "radius = r = 2\r\n" );
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document.write( "So substitute (3) for h, (-1) for k and (2) for r.\r\n" );
document.write( "DO NOT substitute anything for x or y, but leave them \r\n" );
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document.write( "(x - (3))² + (y - (-1))² = (2)²\r\n" );
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document.write( "(x - 3)² + (y + 1)² = 4\r\n" );
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document.write( "That's the answer in standard form.  If you like you can\r\n" );
document.write( "do some algebra on that and come up with the general form\r\n" );
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document.write( "x² + y² + Dx + Ey + F = 0\r\n" );
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document.write( "which will come out to be\r\n" );
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document.write( "x² + y² - 6x + 2y + 6 = 0\r\n" );
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document.write( "Edwin
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