document.write( "Question 189663: Distance from a Point to a Line
\n" ); document.write( "13.The equation of a circle with centre O(0,0)is x^2+y^2=10.The points P(1,3) and Q(-3,-1)are endpoints of chord PQ.Find the exact distance from the centre of the circle to the chord.\r
\n" ); document.write( "\n" ); document.write( "Thank you alot..
\n" ); document.write( "

Algebra.Com's Answer #142346 by Edwin McCravy(20054)\"\" \"About 
You can put this solution on YOUR website!
Distance from a Point to a Line
\n" ); document.write( "13.The equation of a circle with centre O(0,0)is x^2+y^2=10.The points P(1,3) and Q(-3,-1)are endpoints of chord PQ.Find the exact distance from the centre of the circle to the chord.
\n" ); document.write( "Thank you alot..
\n" ); document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "The distance from the center to the chord is the\r\n" );
document.write( "perpendicular distance. So let's draw a line segment\r\n" );
document.write( "from the center perpendicular to the chord. Label the point\r\n" );
document.write( "where it intersects the chord R:\r\n" );
document.write( "\r\n" );
document.write( " \r\n" );
document.write( "\r\n" );
document.write( "Drow OP and OQ:\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\"DELTA\"OPQ is isosceles because its two legs \r\n" );
document.write( "OP and OQ are radii of the same circle and thus\r\n" );
document.write( "are equal.\r\n" );
document.write( "\r\n" );
document.write( "Therefore the altitude OR is the perpendicular \r\n" );
document.write( "bisector of PQ.\r\n" );
document.write( "\r\n" );
document.write( "Therefore R is the midpoint of PQ\r\n" );
document.write( "\r\n" );
document.write( "We use the midpoint formula\r\n" );
document.write( "\r\n" );
document.write( "The midpoint between (\"x%5B1%5D\",\"y%5B1%5D\") and (\"x%5B2%5D\",\"y%5B2%5D\") is given by\r\n" );
document.write( "\r\n" );
document.write( "(\"%28x%5B1%5D%2Bx%5B2%5D%29%2F2\", \"%28y%5B1%5D%2By%5B2%5D%29%2F2\")\r\n" );
document.write( "\r\n" );
document.write( "So the midpoint R between P(1,3) and Q(-3,-1) is\r\n" );
document.write( "\r\n" );
document.write( "R(\"%28%281%29%2B%28-3%29%29%2F2\", \"%28%283%29%2B%28-1%29%29%2F2\")\r\n" );
document.write( "\r\n" );
document.write( "R(\"%28-2%29%2F2\", \"2%2F2\")\r\n" );
document.write( "\r\n" );
document.write( "R(-1,1)\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Now we use the distance formula to find the\r\n" );
document.write( "distance OR from O(0,0) to R(-1,1)\r\n" );
document.write( "\r\n" );
document.write( "Distance formula:\r\n" );
document.write( "\r\n" );
document.write( "\"D+=+sqrt%28%28x%5B2%5D-x%5B1%5D%29%5E2%2B+%28y%5B2%5D-y%5B1%5D%29%5E2%29\"\r\n" );
document.write( "\r\n" );
document.write( "\"OR+=+sqrt%28%28%28-1%29-%280%29%29%5E2%2B+%28%281%29-%280%29%29%5E2%29\"\r\n" );
document.write( "\r\n" );
document.write( "\"OR+=+sqrt%28%28-1%29%5E2%2B+%281%29%5E2%29\"\r\n" );
document.write( "\r\n" );
document.write( "\"OR+=+sqrt%281%2B1%29\"\r\n" );
document.write( "\r\n" );
document.write( "\"OR+=+sqrt%282%29\"\r\n" );
document.write( "\r\n" );
document.write( "Edwin
\n" ); document.write( "
\n" );