document.write( "Question 1145401: Find the distance between the pair of parallel lines.\r
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Algebra.Com's Answer #766648 by ikleyn(52778) $\"\"$ $\"About$

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document.write( "Actually, the distance between two parallel lines on a plane is the length of (any) perpendicular between these lines.\r\n" );
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document.write( "To find the distance in this case, take any point on one line and calculate its distance from the second line.\r\n" );
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document.write( "For simplicity, put x= 0 and from the first equation find  y= 2*0 + 4 = 4.\r\n" );
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document.write( "Thus the point (0,4) lies on the first line.\r\n" );
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document.write( "To find the distance from this point (0,4) to the line y = 2x - 4, use the general formula\r\n" );
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document.write( "for the distance from the point (p,q) on the coordinate plane to the line  Ax + BY + C = 0\r\n" );
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document.write( "    d = .\r\n" );
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document.write( "In your case the point is (0,4) and the line is 2x - y - 4 = 0,  so  A= 2, B= -1, C= -4, p= 0  and  q= 4,\r\n" );
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document.write( "and the formula (1) takes the form\r\n" );
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document.write( "    d =  =  =  =  = 3.577 (approximately).   ANSWER\r\n" );
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\n" ); document.write( "\n" ); document.write( "On formula (1), see the lessons\r
\n" ); document.write( "\n" ); document.write( "    - The distance from a point to a straight line in a coordinate plane \r
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