Write the equation that satisfies the stated conditions. There \r\n" );
document.write( "may be more than one cirle that satifies the equation. Express the \r\n" );
document.write( "final equations in form x^2+y^2+Dx+Ey+F=0\r\n" );
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document.write( "Tangent to the x axis, a radius of length 4, and abscissa of center is -3.\r\n" );
document.write( "I am so totally lost with this one that I don't even know where to start.\r\n" );
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document.write( "First draw a sketch of such a circle:\r\n" );
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document.write( "So you can see that the center would have to be 4 units above the bottom\r\n" );
document.write( "point of the circle. So the center of that circle would have to be\r\n" );
document.write( "(h, k) = (-3, 4). So we use the standard form of a circle with center\r\n" );
document.write( "(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( "and substitute h = -3, k = 4, and r = 4\r\n" );
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document.write( " (x + 3)² + (y - 4)² = 4²\r\n" );
document.write( " (x + 3)² + (y - 4)² = 16\r\n" );
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document.write( "Then multiply that out and collect terms and\r\n" );
document.write( "rearrange the equation in the form\r\n" );
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document.write( " x² + y² + Dx + Ey + F = 0\r\n" );
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document.write( "and you'll get\r\n" );
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document.write( " x² + y² + 6x - 8y + 9 = 0 \r\n" );
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document.write( "Now notice that you could have sketched the circle to hang down\r\n" );
document.write( "below the x-axis instead of sitting on top of it:\r\n" );
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document.write( "
\r\n" );
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document.write( "So you can see that the center in this case would have to be 4 units \r\n" );
document.write( "below the top point of the circle. So the center of that circle would \r\n" );
document.write( "have to be (h, k) = (-3, -4). So again we use the standard form of a \r\n" );
document.write( "circle 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( "and substitute h = -3, k = -4, and r = 4\r\n" );
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document.write( " (x + 3)² + (y + 4)² = 4²\r\n" );
document.write( " (x + 3)² + (y + 4)² = 16\r\n" );
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document.write( "Then multiply that out and collect terms and\r\n" );
document.write( "rearrange the equation in the form\r\n" );
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document.write( " x² + y² + Dx + Ey + F = 0\r\n" );
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document.write( "and you'll get\r\n" );
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document.write( " x² + y² + 6x + 8y + 9 = 0 \r\n" );
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document.write( "Edwin
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