document.write( "Question 1154497: The line y = x + 2 intersects the circle x2 + y2 = 10 in two points. Call the third- quadrant point R and the first-quadrant point E, and find their coordinates. Let D be the point where the line through R and the center of the circle intersects the circle again. The chord DR is an example of a diameter. Show that triangle RED is a right triangle.
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Algebra.Com's Answer #776960 by Edwin McCravy(20060)\"\" \"About 
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The line y = x + 2 intersects the circle x2 + y2 = 10 in two points. Call the
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document.write( "Find the coordinates of the points of intersection E and R:\r\n" );
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document.write( "We use the slope formula to find the slope of RE:\r\n" );
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document.write( "By symmetry, since R=(-3,-1), we can tell that D=(3,1)\r\n" );
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document.write( "We also use the slope formula to find the slope of ED:\r\n" );
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document.write( "So RE and ED are perpendicular because their slopes are negative\r\n" );
document.write( "reciprocals of each other.  So RED is a right triangle.\r\n" );
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document.write( "Edwin
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